Question

In the given figure, lines $AB$ and $CD$ intersect at point $O$.​(i) find the value of $\angle a$.

Answer 1

Given, $AB$ and $CD$ are lines which interect at point $O$.

To find : The value of $\angle a$


Now, Since $AB$ is a straight line

$\therefore$ $\angle AOB={180}^{\circ }$

$\angle AOC+\angle BOC={180}^{\circ }$ [from fig]

${68}^{\circ }+a={180}^{\circ }$ [Given]

$a={180}^{\circ }=-{68}^{\circ }$

$\therefore$ $a={112}^{\circ }$

Hence, the value of $a$ is ${112}^{\circ }$.