Question

Angles$x$and $y$ are adjacent . Find if their exterior arms are in a straight line when : $x=\frac{2}{3}rightangle,y=120⁰$.

Answer 1

Checking whether the exterior arms of angles are in straight line or not :

Here $x=\frac{2}{3}rightangle=\frac{2}{3}\times 90°=60°$

Again $x$and $y$ are adjacent angles.

Now, sum of adjacent angles $=x+y=60°+120°=180°$

Since, the sum of adjacent angles are $180°$, so they form a linear pair.

Hence, the exterior arms of given angles are in straight line.