Law of Sines Calculator

Find a missing side using the law of sines.

Side b 9.431

Formula: a / sin(A) = b / sin(B)

Step-by-step with your numbers:

1. Values used:

2. Known side a = 7

3. Angle A (opposite a) = 40 °

4. Angle B (opposite b) = 60 °

6. Side b = 9.431

Did we solve your problem today?

Relate sides and their opposite angles in any triangle.

The math behind it

a ÷ sin(A) = b ÷ sin(B), so b = a × sin(B) ÷ sin(A).

a 7, A 40°, B 60° → b ≈ 9.43.

Third angle?

C = 180 − A − B; then find side c the same way.