Step-by-step explanation: 5x and the angle next to 9x would be equal to 8x and 5x and the angle next to 8x would be equal to 9x. So the angles that are not given would be 4x and 3x. If you add all of the angles up inside the triangle (5x + 4x + 3x) it equals 12. A triangle has 180 degrees so we have to divide 180 by 12 which comes out to ***15***
