Start by finding the interior angles based on the two given angle measures: 121 + x = 180 x = 59 (subtract 121 from both sides) so the interior angle at the top is 59 144 + y = 180 y = 36 (subtract 144 from both sides) so the interior angle on the right is 36 Now, all three angles of a triangle must have a sum of 180, so x + y + z = 180 59 + 36 + z = 180 (substitute the two interior angle measures into the equation) 95 + z = 180 (simplify the equation) z = 85 (subtract 95 from both sides) Now that we know the interior adjacent angle is 85, we can find the exterior angle (n) n + 85 = 180 n = 95 (subtract 85 from both sides) so, n= 95 degrees
