Let the exterior angle be y. We know that the exterior angle is the sum of opposite two interior angles. Therefore, y = 3x + 90 --- (1) Also, y and 5x - 6 are linear pair. Therefore, y + (5x - 6) = 180 Substituting y = 3x + 90 from (1), we get, (3x + 90) + (5x - 6) = 180 8x + 84 = 180 8x = 180 - 84 = 96 x = 12 degrees Hence, exterior angle y = 3(12) + 90 = 126 degrees.
