Trigonometry and area calculations are essential skills you'll use throughout...
Maths233 views·Updated 17 Aug 2026·2 pagesUnderstanding Sin, Cos, & Tan Coupled with Rectangle Area Calculation
Wendy Mico Avomo@wendymicoavomo_rbcu
1
of 2
Trigonometry: Sin, Cos, and Tan
Trigonometry is all about the relationships between angles and sides in right-angled triangles. Think of it as a way to find missing information when you only know part of the puzzle.
The three main trigonometric ratios are sine (sin), cosine (cos), and tangent (tan). Here's what each one represents: sin = opposite ÷ hypotenuse, cos = adjacent ÷ hypotenuse, and tan = opposite ÷ adjacent.
Remember that the hypotenuse is always the longest side (opposite the right angle), the opposite side is across from your angle, and the adjacent side is next to your angle. A handy memory trick is "SOH CAH TOA" - it contains the first letters of each ratio.
You'll also need to memorise exact values for common angles like 30°, 45°, and 60°. These pop up frequently in exams, so knowing them off by heart will save you time and marks.
Quick Tip: Always label your triangle sides (opposite, adjacent, hypotenuse) before choosing which ratio to use - it prevents silly mistakes!
2
of 2
Area Formulas for Common Shapes
Calculating area is a fundamental skill that appears in nearly every maths exam. Each shape has its own formula, but they're all logical once you understand the pattern.
For rectangles, it's simply area = length × width . Triangles are half of a rectangle, so area = ½ × base × height . Parallelograms work like rectangles: area = base × height .
Trapeziums need a slightly different approach since they have two parallel sides of different lengths. The formula is area = ½ × (sum of parallel sides) × height, written as A = ½ × h.
For circles, you'll use area = π × radius² . Make sure you're using the radius (centre to edge) rather than the diameter (edge to edge through centre). This formula appears constantly in GCSE questions.
Exam Success: Always write down the formula first, then substitute your values - examiners give marks for showing the correct formula even if your final answer is wrong.
We thought you’d never ask...
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Maths233 views·Updated 17 Aug 2026·2 pagesUnderstanding Sin, Cos, & Tan Coupled with Rectangle Area Calculation
Wendy Mico Avomo@wendymicoavomo_rbcu
Trigonometry and area calculations are essential skills you'll use throughout your maths GCSE and beyond. These formulas might look intimidating at first, but they're actually straightforward tools that help solve real-world problems.
1
of 2
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Trigonometry: Sin, Cos, and Tan
Trigonometry is all about the relationships between angles and sides in right-angled triangles. Think of it as a way to find missing information when you only know part of the puzzle.
The three main trigonometric ratios are sine (sin), cosine (cos), and tangent (tan). Here's what each one represents: sin = opposite ÷ hypotenuse, cos = adjacent ÷ hypotenuse, and tan = opposite ÷ adjacent.
Remember that the hypotenuse is always the longest side (opposite the right angle), the opposite side is across from your angle, and the adjacent side is next to your angle. A handy memory trick is "SOH CAH TOA" - it contains the first letters of each ratio.
You'll also need to memorise exact values for common angles like 30°, 45°, and 60°. These pop up frequently in exams, so knowing them off by heart will save you time and marks.
Quick Tip: Always label your triangle sides (opposite, adjacent, hypotenuse) before choosing which ratio to use - it prevents silly mistakes!
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Area Formulas for Common Shapes
Calculating area is a fundamental skill that appears in nearly every maths exam. Each shape has its own formula, but they're all logical once you understand the pattern.
For rectangles, it's simply area = length × width . Triangles are half of a rectangle, so area = ½ × base × height . Parallelograms work like rectangles: area = base × height .
Trapeziums need a slightly different approach since they have two parallel sides of different lengths. The formula is area = ½ × (sum of parallel sides) × height, written as A = ½ × h.
For circles, you'll use area = π × radius² . Make sure you're using the radius (centre to edge) rather than the diameter (edge to edge through centre). This formula appears constantly in GCSE questions.
Exam Success: Always write down the formula first, then substitute your values - examiners give marks for showing the correct formula even if your final answer is wrong.
We thought you’d never ask...
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.
Similar content
Most popular content: Trigonometric Ratios
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Explore the fundamentals of trigonometry, including the tangent, sine, and cosine functions. This summary covers key concepts such as SOH CAH TOA, trigonometric ratios, and methods for finding angles and sides in right triangles. Ideal for students preparing for exams or needing a quick reference.
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