ABCD is a rectangle. Find the length of AB.
AB = 4 * cos-1(3/4) = 3.2
Let FI = 3 IH = 4 FH = 5 EG = height of rectangle = AB
sin IFH = 4/5 =sin EFG
sin EFG / EG = sin G / 4
(4/5) / EG =sin 90 / 4
(4/5)/ EG = 1/ 4
EG = (4/5) /(1/4) = 16/5 = AB
