Exterior Angle

Q.

The sum of all exterior angles of a triangle is

1. ${180}^{\circ }$

2. ${360}^{\circ }$

3. ${540}^{\circ }$

4. ${720}^{\circ }$

Q.

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