Question

In the Fig. , if $l_1||l_2$, the value of $x$ is

• A. $22\frac{1}{2}$
• B. $30$
• C. $45$
• D. $60$

Answer 1

The correct option is C $45$

$2a^{\circ }+2b^{\circ }={180}^{\circ }\therefore a^{\circ }+b^{\circ }={90}^{\circ }nowintriangleABC{180}^{\circ }=a^{\circ }+b^{\circ }+{180}^{\circ }-2x^{\circ }\therefore x^{\circ }=\left(\frac{{90}^{\circ }}{2}\right)={45}^{\circ }$