Question

In a triangle, if the two interior angles ${30}^{\circ }$ and $(x+{20}^{\circ })$ are non-adjacent to an exterior angle $(2x+5^{\circ })$, then find the value of $x$.

• A. ${60}^{\circ }$
• B. ${40}^{\circ }$
• C. ${45}^{\circ }$
• D. ${50}^{\circ }$

Answer 1

The correct option is C ${45}^{\circ }$

$2x+5^{\circ }=x+{20}^{\circ }+{30}^{\circ }$
$2x-x={50}^{\circ }-5^{\circ }$
$x={45}^{\circ }$
Hence, option $\text{D}$ is the correct answer.