What you need to know
Check yourself against these “I can” statements.
- I can label the opposite, adjacent and hypotenuse sides of a right-angled triangle from a marked angle
- I can explain why the ratio of two sides is the same in similar right-angled triangles
- I can recall SOH CAH TOA: sin θ = opposite ÷ hypotenuse cos θ = adjacent ÷ hypotenuse tan θ = opposite ÷ adjacent
- I can choose the right ratio (sin, cos or tan) and use it to find a missing side in a right-angled triangle
Practise this topic
5 resourcesRight-Angled Trigonometry: Mixed Problems
Sides and angles in right-angled triangles, with diagrams drawn to scale and worked solutions one triangle at a time: finding a side or an angle with and without a diagram, two steps, isosceles triangles and trapezia, elevation…
⚙️ WorksheetTrig: Finding Sides
SOH CAH TOA with diagrams drawn to scale: choose the ratio, x on the top, x on the bottom, trig then Pythagoras, trig twice, isosceles triangles, then questions with no diagram. Seven levels, timed, click to reveal.
🧩 ConnectionsPythagoras & Trigonometry
Group Pythagoras, distance-between-points and exact-value trig problems by the length they give. Slips land on other groups from Standard; surds and 3D on Hard.
⬢ BlockbustersRight-Angled Trigonometry: Mixed Problems Blockbusters
Blockbusters with the questions from the Right-Angled Trigonometry: Mixed Problems worksheet: choose its levels for the ordinary hexagons and for the harder ★ ones. Show the answer and the worked solution, or play against the…
⬢ BlockbustersTrig: Finding Sides Blockbusters
Blockbusters with the questions from the Trig: Finding Sides worksheet: choose its levels for the ordinary hexagons and for the harder ★ ones. Show the answer and the worked solution, or play against the computer with multiple…
These are the pages for Trigonometric Ratios: tan, sin and cos in the Year 9 scheme of work, following Pearson Edexcel Maths Progress Delta 3, then GCSE (9–1) Higher (1MA1). Open this topic in Mr Wells Maths to see it alongside the rest of the course.