Question

In the traingle ABC,

if $\angle A=8x-6^o;\angle B=3x+4^{o}and\angle C=4x+2^o$, Calculate $\angle B$

• A. ${20}^o$
• B. ${40}^o$
• C. ${50}^o$
• D. ${45}^o$

Answer 1

The correct option is B ${40}^o$

Using angle sum property of triangle.

$\angle A+\angle B+\angle C={180}^{\circ }\Rightarrow 8x-6^{\circ }+3x+4^{\circ }+4x+2^{\circ }={180}^{\circ }\Rightarrow 15x={180}^{\circ }\Rightarrow x=\frac{{180}^{\circ }}{15}={12}^{\circ }\angle B=3x+4^{\circ }=(3\times {12}^{\circ })+4^{\circ }={40}^{\circ }$