Question

In the figure above, if $\overline{BC}||\overline{DE}$, what is the value of x?

• A. ${30}^o$
• B. ${40}^o$
• C. ${70}^o$
• D. ${110}^o$

Answer 1

The correct option is C ${70}^o$

Given $BC||DE$ and $AD$ is transversal

$\therefore$\angle D=\angle B$ (corresponding angles)

$\therefore \angle D={30}^{\circ }$

Now exterior angle os triangle is equal to sum of interior opposite angles

$\therefore x=\angle A+\angle D$

$x={30}^{\circ }+{40}^{\circ }x={70}^{\circ }$