Question

In the given figure, lines $AB$ and $CD$ intersect at point $O$

(iv). Name all the reflex angles formed and write the measure of each

Answer 1

Step 1: Finding the value of angle $a$



Given,$AB$ and $CD$ are lines which intersect 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]

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

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

$\therefore \angle AOC=\angle DOB={68}^{\circ }$ [Vertically opp. angles] and $\angle BOC=a=\angle AOD={112}^{\circ }$ [Vertically opp. angles]