Math
posted by Christopher .
Mr Shen wished to enter the orange kite competition with an innovative kite of his own desgin. He did tests that showed an irregular quadrilateral design was best. The longest side (A) was twice the length of the shortest side (C). Side B was one and onehalf times the shortest side (C). Side D needed to be 4" (4 inches) longer then side C. If the competition required that the perimeter of your kite must be 81", what were the dimensions of Mr. Shen's Kite?

Side C  x
side A  2x
side B 1.5x
side D  x+4
x + 2x + 1.5x + x+4 = 81
5.5x = 77
x = 14
plug in 14 into each of my definitions to find the lengths 
I got the answers for A and B but how do I do that for C and D?

L A=28
Length B=21
I got those answers can you help me on the other 2?