Question

A ray OC is constructed on the line segment AB such that ∠BOC is x${}^{\circ }$. What will be the measure of ∠AOC in terms of x?

• A. x${}^{\circ }$
• B. 180${}^{\circ }$ - x${}^{\circ }$
• C. 90${}^{\circ }$ - x${}^{\circ }$
• D. 360${}^{\circ }$ - x${}^{\circ }$

Answer 1

The correct option is B

180${}^{\circ }$ - x${}^{\circ }$

AB is a straight line and the ray OC is drawn on the line segment AB. Therefore,

$\angle$AOC + $\angle$BOC = 180${}^{\circ }$ ($\angle$AOC and $\angle$BOC are linear pair of angles)

$\angle$AOC = 180${}^{\circ }$ - $\angle$BOC

= 180${}^{\circ }$ – x${}^{\circ }$