Question

In the given figure, AOC is a straight line. Find:-
(i) x
(ii) ∠AOB
(iii) ∠BOC

Answer 1

We know that ∠AOB and ∠COB are linear pair.

It can be written as $\angle AOB+\angle COB={180}^o$

$x+{25}^o+3x+{15}^o={180}^o$

$4x+{40}^o={180}^o$

$4x={140}^o$

(i) $4x={140}^o$

$x={35}^o$

(ii) $\angle AOB=x+{25}^o$

$\angle AOB={25}^o+{35}^o={60}^o$

(iii) $\angle BOC=3x+{15}^o$

$\angle BOC=(3\times 35)+{15}^o$

$\angle BOC={120}^o$