Triangle x y z is cut by line segment c d. line segment c d goes from side x y to side y z. the length of c d is 15, the length of x z is 18, the length of c y is 25, and the length of y d is 20. lines c d and x z are parallel. if and cx = 5 units, what is dz? 2 units 3 units 4 units 5 units