180
The exterior angle of a triangle + the adjacent interior angle are supplementary, that is sum to 180°, thus
the exterior angle = 180 - adjacent interior angle
Answer:
180º
Step-by-step explanation:
You know that the sum of the inside angles of a triangle is 180º because they are supplementary.
But the other characteristic of a triangle is that the exterior angles summed the interior are also supplementary so, it's 180º.
An exterior angle of a triangle equals 180º minus the adjacent interior angle.
