Question

Mark (✓) against the correct answer in each of the following:
In the given figure, ∠BOC = ?
(a) 45°
(b) 60°
(c) 75°
(d) 56°
Figure

Answer 1

(b) 60°

Since, OAB is a straight line, the sum of all the angles
on the same side of AOB, at point O on it, is 180^o.
$$\begin{gathered} \therefore 3x+5x+4x=180 \\ \Rightarrow 12x=180 \\ \Rightarrow x=15 \\ \therefore \angle BOC=4\times 15=60° \end{gathered}$$