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13 Dec 2025

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Understanding Trigonometry Basics

Trigonometry might seem intimidating, but it's actually just a clever way to find missing sides and angles in... Show more

trigonomerry sin cos, tan
only works on right angles
The inree irigonomerry formulas
1.
Sin x = opposile
2 cos x adjacent
1.
3. jan x= oppos

The Three Trigonometry Formulas

Trigonometry is all about relationships in right-angled triangles, and there are three key formulas you need to remember. Think of them as your mathematical toolkit for solving triangle mysteries!

The three trigonometric ratios are Sin x = opposite/hypotenuse, Cos x = adjacent/hypotenuse, and Tan x = opposite/adjacent. The hypotenuse is always the longest side, the opposite is the side across from your angle, and the adjacent is the remaining side next to your angle.

Here's your game plan first, work out which two sides are involved in your question. Then pick the formula that uses those two sides - it's that simple!

When you need to find an angle, use the inverse function by pressing 'shift' or '2nd' followed by sin, cos, or tan on your calculator. Just make sure your calculator is in DEG mode, and you'll see sinโปยน, cosโปยน, or tanโปยน appear on screen.

Top Tip Remember SOH-CAH-TOA to recall which ratio uses which sides Sin = Opposite/Hypotenuse, Cos = Adjacent/Hypotenuse, Tan = Opposite/Adjacent.

trigonomerry sin cos, tan
only works on right angles
The inree irigonomerry formulas
1.
Sin x = opposile
2 cos x adjacent
1.
3. jan x= oppos

Finding Angles in Triangles

Sometimes you'll encounter isosceles triangles where two sides are equal - don't panic! You can split them down the middle to create a right-angled triangle that you can actually work with.

In the example with a 25m isosceles triangle, splitting it creates a right triangle where the adjacent side becomes 15m and the hypotenuse stays 25m. Since you know adjacent and hypotenuse, you use cosine.

The calculation becomes cos x = 15/25 = 0.6, then use the inverse to find x = cosโปยน(0.6) = 53.1ยฐ. Remember to round to the required decimal places - in this case, 1 decimal place.

The key is identifying which sides you know and which trigonometric ratio connects them. Once you've got that sorted, it's just a matter of plugging numbers into your calculator!

Remember When finding angles, you'll always use the inverse functions (sinโปยน, cosโปยน, tanโปยน) on your calculator - this 'undoes' the original ratio to give you the angle.

We thought youโ€™d never ask...

What is the Knowunity AI companion?

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.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ€“ all at your fingertips.

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Anna

iOS user

Best app on earth! no words because itโ€™s too good

Thomas R

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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

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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.

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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

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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 didnโ€™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 Iโ€™m sure you too will see developments.

Xander S

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THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

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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

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ย 

Maths

โ€ข

438

โ€ข

13 Dec 2025

โ€ข

2 pages

Understanding Trigonometry Basics

Trigonometry might seem intimidating, but it's actually just a clever way to find missing sides and angles in right-angled triangles. Once you master the three basic formulas (sin, cos, and tan), you'll be solving triangle problems like a pro!

trigonomerry sin cos, tan
only works on right angles
The inree irigonomerry formulas
1.
Sin x = opposile
2 cos x adjacent
1.
3. jan x= oppos

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

The Three Trigonometry Formulas

Trigonometry is all about relationships in right-angled triangles, and there are three key formulas you need to remember. Think of them as your mathematical toolkit for solving triangle mysteries!

The three trigonometric ratios are: Sin x = opposite/hypotenuse, Cos x = adjacent/hypotenuse, and Tan x = opposite/adjacent. The hypotenuse is always the longest side, the opposite is the side across from your angle, and the adjacent is the remaining side next to your angle.

Here's your game plan: first, work out which two sides are involved in your question. Then pick the formula that uses those two sides - it's that simple!

When you need to find an angle, use the inverse function by pressing 'shift' or '2nd' followed by sin, cos, or tan on your calculator. Just make sure your calculator is in DEG mode, and you'll see sinโปยน, cosโปยน, or tanโปยน appear on screen.

Top Tip: Remember SOH-CAH-TOA to recall which ratio uses which sides: Sin = Opposite/Hypotenuse, Cos = Adjacent/Hypotenuse, Tan = Opposite/Adjacent.

trigonomerry sin cos, tan
only works on right angles
The inree irigonomerry formulas
1.
Sin x = opposile
2 cos x adjacent
1.
3. jan x= oppos

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Finding Angles in Triangles

Sometimes you'll encounter isosceles triangles where two sides are equal - don't panic! You can split them down the middle to create a right-angled triangle that you can actually work with.

In the example with a 25m isosceles triangle, splitting it creates a right triangle where the adjacent side becomes 15m and the hypotenuse stays 25m. Since you know adjacent and hypotenuse, you use cosine.

The calculation becomes: cos x = 15/25 = 0.6, then use the inverse to find x = cosโปยน(0.6) = 53.1ยฐ. Remember to round to the required decimal places - in this case, 1 decimal place.

The key is identifying which sides you know and which trigonometric ratio connects them. Once you've got that sorted, it's just a matter of plugging numbers into your calculator!

Remember: When finding angles, you'll always use the inverse functions (sinโปยน, cosโปยน, tanโปยน) on your calculator - this 'undoes' the original ratio to give you the angle.

We thought youโ€™d never ask...

What is the Knowunity AI companion?

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.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ€“ all at your fingertips.

7

Smart Tools NEW

Transform this note into: โœ“ 50+ Practice Questions โœ“ Interactive Flashcards โœ“ Full Mock Exam โœ“ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

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Explore the detailed mark scheme for the OCR GCSE Higher Mathematics Paper 6 from June 2018. This resource covers key concepts such as triangle congruence, vector addition, area calculations, and more, providing essential guidance for exam preparation and understanding of marking criteria.

MathsMaths
9

Calculating Quadrilateral Areas

Explore the methods for calculating the area of various quadrilaterals, including squares, rectangles, and parallelograms. This summary covers essential formulas, properties, and examples to enhance your understanding of area and perimeter in geometry.

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Can't find what you're looking for? Explore other subjects.

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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 itโ€™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 didnโ€™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 Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

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 itโ€™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 didnโ€™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 Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

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