# Worksheet: The Cosine Rule

In this worksheet, we will practice using the cosine rule to find missing sides and angles in different triangles.

**Q1: **

Find the length of side of the triangle shown.

**Q2: **

Find the perimeter of the parallelogram shown in the diagram.

**Q3: **

Find the perimeter of the triangle shown in the diagram.

**Q4: **

Find the size of angle , in degrees, of the triangle shown.

**Q5: **

Find the size of angle , in degrees, of the triangle shown.

**Q6: **

Find the length of side of the triangle shown.

**Q7: **

Find the perimeter of the triangle shown in the diagram.

**Q8: **

The diagram shows a triangle with three sides of different lengths.

Find the size of angle in degrees to the nearest degree.

Find the size of angle in degrees to the nearest degree.

Find the size of angle in degrees to the nearest degree.

**Q9: **

Find the perimeter of the triangle shown in the diagram.

**Q10: **

Find the size of angle , in degrees, of the triangle shown in the diagram.