Ratios of Sides

Sine, cosine, tangent

An interactive lesson with 8 steps, about 7 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• In a right triangle, ratios of sides depend only on the angle.
• $\sin = \text{opp}/\text{hyp}$, $\cos = \text{adj}/\text{hyp}$, $\tan = \text{opp}/\text{adj}$.
• Inverse functions ($\sin^{-1}$ and so on) turn a ratio back into an angle.

Steps

1. Big and small
2. Ratios depend only on the angle
3. SOH CAH TOA
4. Find a side
5. Wheelchair ramp
6. How tall is the tree?
7. Working backwards
8. Roof pitch