Questions where students often pick the tempting wrong answer — make sure you know the right one:
When does Pythagoras' theorem (a²+b²=c²) apply?✗ To any triangle.✓ Only to right-angled triangles.
What do sin, cos and tan give you?✗ The angle directly.✓ Ratios of sides — use inverse functions to find an angle.
In Pythagoras' theorem, which side does c^2 represent?✗ c^2 represents any side of the triangle as long as the other two are squared.✓ The hypotenuse — the longest side, opposite the right angle.
Can Pythagoras' theorem be used on any triangle?✗ Yes — it works on any triangle as long as you square the sides.✓ No — it only applies to right-angled triangles.
Does sin(2x) equal 2 sin(x)?✗ Sin is a function, so sin(2x) = 2 sin(x) by pulling the constant out.✓ No — sin is not a linear function: sin(2 × 30°) = sin 60° ≈ 0.87, but 2 sin 30° = 1.
Practise Trigonometry & Pythagoras — free games
Test yourself with these quick revision games for this topic:
