Question

Find the value of $x$, where AB || CD

• A. ${70}^{\circ }$
• B. ${45}^{\circ }$
• C. ${125}^{\circ }$

Answer 1

Since AB || CD, $\angle A+\angle C={180}^{\circ }$ (co-interior angles are supplementary)
$\therefore x=\angle C={180}^{\circ }-{110}^{\circ }={70}^{\circ }$


Since AB || CD, $\angle B=\angle C$ (alternate interior angles are equal)
$\therefore x=\angle C={45}^{\circ }$


Since AB || CD, $\angle B=\angle D$ (corresponding angles)
$\therefore x=\angle D={125}^{\circ }$