SOHCAHTOA is a powerful trigonometric tool for solving right-angled triangle... Show more
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287
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Updated Mar 25, 2026
•
Shaz
@shaz2007
SOHCAHTOA is a powerful trigonometric tool for solving right-angled triangle... Show more

This page focuses on using SOHCAHTOA to find missing angles in right-angled triangles. It explains the process of using inverse trigonometric functions to calculate unknown angles.
The steps for finding missing angles are:
Highlight: To find an angle, we use inverse trigonometric functions: sin⁻¹, cos⁻¹, or tan⁻¹.
The page provides examples for each trigonometric ratio:
Using sine:
Example: If O = 8.4 and H = 10.8, then θ = sin⁻¹(8.4 ÷ 10.8) ≈ 51.1° (3 sf)
Using cosine:
Example: If A = 12 and H = 14.19, then θ = cos⁻¹(12 ÷ 14.19) ≈ 32.3° (3 sf)
Using tangent:
Example: If O = 11.2 and A = 7.8, then θ = tan⁻¹(11.2 ÷ 7.8) ≈ 55.1° (3 sf)
Vocabulary: Inverse trigonometric functions (also called arcfunctions):
- sin⁻¹ or arcsin
- cos⁻¹ or arccos
- tan⁻¹ or arctan
The page also provides guidance on using a calculator for these inverse functions, typically accessed through the 'shift' or 'inverse' button followed by the regular trigonometric function key.
Highlight: Always remember to use the appropriate units (degrees or radians) and round your answers to a suitable number of significant figures or decimal places as required by the question.

This page introduces the fundamental concept of SOHCAHTOA and its application in solving right-angled triangle problems. It covers the basics of finding missing lengths using trigonometric ratios.
Definition: SOHCAHTOA is a mnemonic device used to remember the ratios in trigonometry for sine, cosine, and tangent.
The page explains how to label the sides of a right-angled triangle:
Highlight: The hypotenuse is always the diagonal and opposite the right angle.
To find missing lengths, the process involves:
Example: To find H when O and the angle are given, use H = O ÷ sin θ. For instance, if O = 10.2 and θ = 64°, then H = 10.2 ÷ sin(64) ≈ 11.3 cm (3 sf).
The page also provides examples for finding the adjacent side using cosine and the opposite side using tangent.
Vocabulary:
- SOH: Sine = Opposite ÷ Hypotenuse
- CAH: Cosine = Adjacent ÷ Hypotenuse
- TOA: Tangent = Opposite ÷ Adjacent
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Shaz
@shaz2007
SOHCAHTOA is a powerful trigonometric tool for solving right-angled triangle problems. It helps find missing angles and sides using sine, cosine, and tangent ratios. This guide explains how to use SOHCAHTOA for various calculations in right-angled triangles.

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Improve your grades
Join milions of students
This page focuses on using SOHCAHTOA to find missing angles in right-angled triangles. It explains the process of using inverse trigonometric functions to calculate unknown angles.
The steps for finding missing angles are:
Highlight: To find an angle, we use inverse trigonometric functions: sin⁻¹, cos⁻¹, or tan⁻¹.
The page provides examples for each trigonometric ratio:
Using sine:
Example: If O = 8.4 and H = 10.8, then θ = sin⁻¹(8.4 ÷ 10.8) ≈ 51.1° (3 sf)
Using cosine:
Example: If A = 12 and H = 14.19, then θ = cos⁻¹(12 ÷ 14.19) ≈ 32.3° (3 sf)
Using tangent:
Example: If O = 11.2 and A = 7.8, then θ = tan⁻¹(11.2 ÷ 7.8) ≈ 55.1° (3 sf)
Vocabulary: Inverse trigonometric functions (also called arcfunctions):
- sin⁻¹ or arcsin
- cos⁻¹ or arccos
- tan⁻¹ or arctan
The page also provides guidance on using a calculator for these inverse functions, typically accessed through the 'shift' or 'inverse' button followed by the regular trigonometric function key.
Highlight: Always remember to use the appropriate units (degrees or radians) and round your answers to a suitable number of significant figures or decimal places as required by the question.

Access to all documents
Improve your grades
Join milions of students
This page introduces the fundamental concept of SOHCAHTOA and its application in solving right-angled triangle problems. It covers the basics of finding missing lengths using trigonometric ratios.
Definition: SOHCAHTOA is a mnemonic device used to remember the ratios in trigonometry for sine, cosine, and tangent.
The page explains how to label the sides of a right-angled triangle:
Highlight: The hypotenuse is always the diagonal and opposite the right angle.
To find missing lengths, the process involves:
Example: To find H when O and the angle are given, use H = O ÷ sin θ. For instance, if O = 10.2 and θ = 64°, then H = 10.2 ÷ sin(64) ≈ 11.3 cm (3 sf).
The page also provides examples for finding the adjacent side using cosine and the opposite side using tangent.
Vocabulary:
- SOH: Sine = Opposite ÷ Hypotenuse
- CAH: Cosine = Adjacent ÷ Hypotenuse
- TOA: Tangent = Opposite ÷ Adjacent
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential trigonometric ratios and formulas for solving right triangles. This summary covers the SOH CAH TOA method, step-by-step calculations, and practical examples to help you master GCSE Maths concepts. Ideal for students preparing for exams.
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Explore key concepts of GCSE Circle Theorems, including angles at the center, cyclic quadrilaterals, angles in a semi-circle, and properties of tangents. This summary provides clear explanations and essential formulas to help you master this topic for your exams.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user