The angles of a quadrilateral add up to 360 degrees. If you add up the angles, and solve the equation, you get q = 25. Therefore, the largest angle is 5q + 15 = 140 degrees.

The angles of a quadrilateral add up to 360 degrees. If you add up the angles, and solve the equation, you get q = 25. Therefore, the largest angle is 5q + 15 = 140 degrees.