# Worksheet: The Cosine Ratio

In this worksheet, we will practice finding missing lengths and angles in a triangle using the cosine ratios.

**Q8: **

is a triangle, where , , and . Find the length of , giving your answer to the nearest centimeter.

**Q18: **

is an isosceles trapezoid where and . Find and giving the answer to the nearest second.

- A,
- B,
- C,
- D,

**Q21: **

In the given figure, the two triangles are similar.

Work out the value of for . Give your answer as a fraction in its simplest form.

- A
- B
- C
- D
- E

Work out the value of for . Give your answer as a fraction in its simplest form.

- A
- B
- C
- D
- E

What can be said about the value of for two similar triangles?

- AThey are often equal.
- BThey are always equal.
- CThere is no relation.

**Q22: **

Find the value of .

**Q23: **

is an isosceles triangle where and . Find the value of given lies on where .

- A
- B
- C
- D
- E

**Q24: **

A ladder is leaning against a vertical wall where the angle of inclination with the ground is . The lower end of the ladder moves metres away from the wall and the angle of inclination becomes . Find the length of the ladder giving the answer to one decimal place.

**Q25: **

Find given is an isosceles triangle where and . Give the answer to the nearest second.

- A
- B
- C
- D