The interior angles of a triangle must add up to 180 eighty degrees. Since the ratio is 7:5:3, let's say that the three angles have degrees 7x, 5x, and 3x 7x+5x+3x = 15x = 180 -> x = 12 Therefore, the three angles are 7*12=84, 5*12=60, 3*12=36 degrees.
