1. Trigonometry – Finding Side Lengths

2. Calculator Check
All scientific or CAS calculators can produce accurate values
for sin θ, cos θ and tan θ
**Ensure that your calculator is in degree mode**
Find the following:
Sin(30°) =
Cos(45°) =
Tan(15°) =

3. Finding the side length
If the angle and one side length of a right angled triangle is known then the other side lengths can be found using the sin θ, cos θ and tan θ ratios.
Label the sides
O, A, H
2. Choose the correct ratio – SOHCAHTOA
3. Substitute the values into the formula
4. Rearrange the formula to make x the subject

4. Label the sides
O, A, H
2. Choose the correct ratio – SOHCAHTOA
3. Substitute the values into the formula
4. Rearrange the formula to make x the subject

5. Label the sides
O, A, H
2. Choose the correct ratio – SOHCAHTOA
3. Substitute the values into the formula
4. Rearrange the formula to make x the subject

6. Exercise 3f – Finding Side Lengths
Cambridge Text Complete the following questions 2a, b, c 3a, d, f, g 4b, d, e, f, g, I 5a, c, f, i, j, m, n ,p 6, 7, 8