20.6 The sine rule — Practise

Work independently. Estimate where useful, show your method, and check units. In the mixed questions, choose the method and give a reason.

1. H In triangle ABC, A=30°, B=45°, and side a=6 cm. Find side b to 1 decimal place.
2. H In a triangle, A=60°, a=10 cm and B=30°. Find b.
3. H In a triangle, a=8 cm, A=30° and b=12 cm. Find all possible values of angle B to 1 decimal place.
4. H In a triangle, A=90°, a=14 cm and B=30°. Find b.
5. H In a triangle, side a=5 cm opposite 30° and side b is opposite 90°. Find b.
6. H In triangle ABC, A=45°, B=60°, and a=10 cm. Find c, where C is the remaining angle.
7. H A triangle has a=7 cm, A=30°, b=10 cm. Find both possible values of B to 1 decimal place.
8. H In a triangle, a=9 cm, A=40°, and C=80°. Find c to 3 significant figures.