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?
+128448 Note that triangles DXE and EYF have the same height as triangle DEF and their combined bases = DF
So.....their total areas must be the same as the area of triangle DEF
Since rectangle DXYF = 40......then it is composed of two equal areas .....
So.......[ DEF ] = 40 / 2 = 20
