Circle O is inscribed in quadrilateral ABCD. The circle intersects the quadrilateral at points W, X, Y and Z. The sum of side lengths of AB and DC equals 48 cm, what is the sum of the side lengths of BC and AD?

Question

Circle O is inscribed in quadrilateral ABCD. The circle intersects the quadrilateral at points W, X, Y and Z. The sum of side lengths of AB and DC equals 48 cm, what is the sum of the side lengths of BC and AD?
sorry it won't let me add a picture :/
help is greatly appreciated !!

oobleck · Answer

it is easy to show that |AB|+|CD| = |BC|+|DA| google for examples