Answer:
b = 13.8
A = 45°
C = 35°
Step-by-step explanation:
Given:
m<B = 100°
a = 10
c = 8
Required:
b, m<C, and m<A
✔️Find b using Cosine Rule:
b² = a² + c² - 2*ac*Cos(B)
Plug in the values
b² = 10² + 8² - 2*10*8*Cos(100)
b² = 164 - (-27.7837085)
b² = 191.783709
Take the square root of both sides
b = 13.8 (nearest tenth)
✔️Find m<C using Sine rule:
[tex] \frac{Sin(C)}{c} = \frac{Sin(B)}{b} [/tex]
Plug in the values
[tex] \frac{Sin(C)}{8} = \frac{Sin(100)}{13.8} [/tex]
Multiply both sides by 8
[tex] \frac{Sin(C)}{8} \times 8 = \frac{Sin(100)}{13.8} \times 8 [/tex]
[tex] Sin(C) = \frac{Sin(100) \times 8}{13.8} [/tex]
[tex] Sin(C) = 0.5709 [/tex]
[tex] C = Sin^{-1}(0.5709) [/tex]
[tex] C = 35 [/tex] (nearest degree)
m<C = 35°
✔️m<A = 180 - (100 + 35) (sum of triangle)
m<A = 180 - 135
m<A = 45°
