Question

Solve a triangle when A=40°, C=70°, and a=20.

Answer 1

Answer:

The answer is (c) ⇒ B = 70° , b = 29.2 , c = 29.2

Step-by-step explanation:

∵ m∠A = 40° , m∠C = 70°

∴ m∠B = 180 - (40 + 70) = 70°

By using sin rule

∵ $\frac{a}{sinA}=\frac{b}{sinB}=\frac{c}{sinC}$

∵ a = 20

∵ $\frac{20}{sin40}=\frac{b}{sin70}$

∴ $b=\frac{20sin70}{sin40} =29.2$

∴ $\frac{20}{sin40}=\frac{c}{sin70}$

∴ $c=\frac{20sin70}{sin40}=29.2$

∴ m∠B = 70° , b = 29.2 , c = 29.2