first you know that you have 2 and 5 as similar numbers you both square them so that they become a ratio of area which is 4/25 after you do 4/25=20/x and you do cross multiply then you find 125. hope that helped understand.
The Exterior Angle of a Triangle Formula states that the measure of an exterior angle is equal to the sum of its remote interior angles. Therefore, r + 58 = 130 which means r = 72°.