Trigonometry

triangle measure

1. measuring right-angled triangles• What can be said about these triangles? Can you find

all the missing angles and sides?

30°

30°

30°

30°

1cm

0.5cm

3cm

2.5cm

5cm

b

a

cA

C

B

• which ratio? which sides/angles?• calculator use – sin or sin-1?• finding the length ‘on the bottom’ of the ratio

• problem solving: where is the triangle?

A practical problem

• How high is ….

Generalising trigonometric functions

• How to interpret sin/cos/tan for angles greater than 90°?

• unit circle app

‘special’ angles: 45°, 60°, 30° (π/4, π/3, π/6)

1

45°

60° 60°

1