Final answer:
The correct relationship between an exterior angle and an interior angle of a polygon is that the sum of the two adjacent angles equals 180 degrees, thus the equation is 2)Exterior Angle = 180 - Interior Angle.
Step-by-step explanation:
The relationship between an exterior angle and an interior angle is important in understanding geometric figures. When dealing with any polygon, and specifically a triangle, the sum of the exterior angle and the interior angle that are adjacent to each other always equals 180°. This is because they form a linear pair, which is a pair of adjacent angles whose non-common sides are opposite rays.
Therefore, the correct equation that shows this relationship is option 2) Exterior Angle = 180 - Interior Angle. This means that if you know the measure of an interior angle, you can easily find its exterior angle by subtracting the interior angle's measure from 180°. Conversely, if you have the measure of an exterior angle, you can find the interior angle's measure by subtracting the exterior angle's measure from 180°.