Question

In the above figure, which one of the following is not true ($c\parallel d,a\parallel b$)?

(a) $\angle 1+\angle 5={180}^{\circ }$
(b) $\angle 2+\angle 5={180}^{\circ }$
(c) $\angle 3+\angle 4={180}^{\circ }$
(d) $\angle 2+\angle 3={180}^{\circ }$

Answer 1

The correct option is B. $\angle 2+\angle 5={180}^{\circ }$

$\angle 2$ and $\angle 5$ are vertically opposite angle and hence, $\angle 2+\angle 5\ne {180}^{\circ }$