Q24:
C = 40°
Length BC = 8.4 cm
Area = 100 cm(2)
Area = ½ a b sin C:
100 / sin 40° = 155.57
155.57 / 8.4 = 18.52
18.52 / 0.5 = 37.04
Cosine rule = a2 = b2 + c2 - 2bc Cos A
37.04(2) + 8.4(2) - 2 x 37.04 x 8.4 x cos 40 = 965.8974663
square root of 965.90 = 31.1
Answer = 31.1