Solution 1: Since AF is parallel to CE, the area of shaded region is the same area as blue triangle, because these two triangle have the same base CE and same height. Hence the shaded region is half of 13*13, which is 84.5

Solution 2: Well, the more standard solution would be to use the total area of the two squares, subtract the yellow, green and orange triangles, which is 17*17 +13*13= 468 (total)

yellow is 17*30/2=255, green is 17*4/2=34, orange is 13*13/2=84.5

So 468-255-34-84.5=84.5