PrepWisePrepWiseExact Trig Values
Geometry & MeasuresIntroduction

The Special Triangles

Part of Exact Trig Values — GCSE Mathematics

This introduction covers The Special Triangles within Exact Trig Values for GCSE Mathematics. Revise Exact Trig Values in Geometry & Measures for GCSE Mathematics with 14 exam-style questions and 4 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 1 of 6 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 1 of 6

Practice

14 questions

Recall

4 flashcards

The Special Triangles

For certain angles, trig values can be written exactly using surds and fractions - no decimals needed! These come from two special triangles: the 45-45-90 isosceles and the 30-60-90 from splitting an equilateral. Learn the pattern - you WILL need these!

Keep building this topic

Read this section alongside the surrounding pages in Exact Trig Values. That gives you the full topic sequence instead of a single isolated revision point.

The Values You MUST KnowMemory TricksWorked Example 1

Practice Questions for Exact Trig Values

What is the exact value of sin 30°?

  • A. √3/2
  • B. 1/2
  • C. √2/2
  • D. 1
1 markfoundation

James says that sin 30° and cos 60° are equal. Is James correct? Explain your answer using exact values.

2 marksstandard

Quick Recall Flashcards

Sin Pattern
sin 0°=0, sin 30°=1/2, sin 45°=√2/2, sin 60°=√3/2, sin 90°=1. Pattern: √n/2 for n=0,1,2,3,4
Cos Pattern
Cos is sin BACKWARDS. cos θ = sin(90°-θ). So cos 30° = sin 60°, etc.

Want to test your knowledge?

PrepWise has 14 exam-style questions and 4 flashcards for Exact Trig Values — with adaptive difficulty and instant feedback.

Join Alpha

Back to

Exact Trig Values

Next

The Values You MUST Know