Final answer:
To find an exterior angle of a triangle, you will need the 2 remote interior angles. With these, you can sum them to find the measure of the exterior angle because the exterior and adjacent interior angles always sum to 180 degrees.
Step-by-step explanation:
To find the measure of an exterior angle of a triangle, you will need to know the measures of the 2 remote interior angles. An exterior angle of a triangle is equal to the sum of the two remote interior angles, which are the angles inside the triangle that are not adjacent to the exterior angle in question. This is because the sum of the interior angle and its adjacent exterior angle is always 180 degrees, as they form a straight line. Therefore, the exterior angle is equal to the difference between 180 degrees and the measure of the interior angle adjacent to it. Since the sum of the interior angles of a triangle is 180 degrees, you can subtract the angle adjacent to the exterior angle from 180 degrees to find the measure of the desired exterior angle.