- Use the Law of SInes to find the measure of angle C:
(sinC)/c = (sinA)/a
sincC = c(sinA)/a
C = sin⁻¹(c·sinA / a)
Plugging in numbers:
C = sin⁻¹(83·sin(31) / 44)
= sin⁻¹(0.97155)
= 76.3°
- We know that the sum of the internal angles of a triangle is 180°, therefore:
B = 180 - (A + C)
= 180 - (31 + 76.3)
= 180 - 107.3
= 72.7°
- Therefore the corret answer is C: angle B is 72.7°
