Question

in the give figure if AOB is a straight line then angle BOC is ​

Answer 1

Mate you have to apply the formula of LINEAR PAIR OF ANGLE

Therefore ,

$2 x + 30 + 2x + 10 = 180 \\ 4x + 40 = 180 \\ 4x = 180 - 40 \\ 4x = 140 \\ x = \frac{140}{4} \\ x = 35$

Therefore , angleAOC = 100° and angleBOC = 80°