IF EC = 8, than we know for sure that the length of AC would be 2 x 8 = 16
The formula to use in determining Rhombus area is
A = (AC . DB)/2 , so the value x could be found with this equation :
72 = 16 (x-1) / 2
72 = (16x -16) /2
72 = 8x - 8
80 = 8x
x = 10
