Pre Calculus 11 - Trigonometry

Question

In triangleABC, AB=5, BC=3 and ∠BAC= 20°. Find all possible values of ∠C.

Answer 1

Using the Law of Sines, sinC / 5 = sin20° / 3

3sinC = 5sin20°

sinC = 0.570033572

∠C = Sin^-1(0.570033572) or 180° - Sin^-1(0.570033572) = 34.75° or 145.25°