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
∵ [tex]\frac{a}{sinA}=\frac{b}{sinB}=\frac{c}{sinC}[/tex]
∵ a = 20
∵ [tex]\frac{20}{sin40}=\frac{b}{sin70}[/tex]
∴ [tex]b=\frac{20sin70}{sin40} =29.2[/tex]
∴ [tex]\frac{20}{sin40}=\frac{c}{sin70}[/tex]
∴ [tex]c=\frac{20sin70}{sin40}=29.2[/tex]
∴ m∠B = 70° , b = 29.2 , c = 29.2
