In the diagram below, BE = EC = DF and ADF has the same area as DEF If rectangle DXYF has area 40, what is the area of DEF?
+37159 Rectangle area of 40 has base = x and height = 1/2 x
x * 1/2 x = 40
x = sqrt 80 triangle has height = 1/2 *sqrt 80 and base sqrt 80 area = 1/2 base * height = 20 units2
