Let
x--------> the measure of the adjacent interior angle
y--------> the measure of an exterior angle at the vertex of a polygon
we know that
The measure of the adjacent interior angle and the measure of an exterior angle at the vertex of a polygon are supplementary angles
so
°
<u>Examples</u>
case 1)
<u>In a square</u>
°
so
°
In this case
The measure of an exterior angle at the vertex of a polygon equals the measure of the adjacent interior angle
case 2)
<u>an equilateral triangle</u>
°
so
°
In this case
The measure of an exterior angle at the vertex of a polygon is not equals the measure of the adjacent interior angle
therefore
<u>the answer is</u>
sometimes
