Question

In the figure, AB || CD and XY is the transversal.

Which of the following is incorrect?

• A. $p={115}^{\circ }$
• B. $q={115}^{\circ }$
• C. $q={65}^{\circ }$
• D. $r={115}^{\circ }$

Answer 1

The correct option is B

$q={115}^{\circ }$

Co-interior angles are supplementary,
$\Rightarrow q+{115}^{\circ }={180}^{\circ }$

$\Rightarrow q={180}^{\circ }-{115}^{\circ }={65}^{\circ }$.

Also, p+q = ${180}^{\circ }$ ( Angles in straight line )
$\Rightarrow p={115}^{\circ }$.

Also p = r = 115${}^{\circ }$ and
q = y = 65${}^{\circ }$ (Vertically opposite angles are equal).