As shown in the figure, △ ABC is an isosceles right triangle, D is the midpoint of AB, ab = 2, and the center angles of sector ADG and BDH are all equal to 90 degrees

As shown in the figure, △ ABC is an isosceles right triangle, D is the midpoint of AB, ab = 2, and the center angles of sector ADG and BDH are all equal to 90 degrees

∵ ABC is isosceles right triangle, D is the midpoint of AB, ab = 2, ≌ ad = BD = AE = WB = 1, ≌ cab = ∠ CBA = 45 °, ≁ EF ⊥ AB, WS ⊥ AB, ≌ AEF and △ WSB are isosceles right triangles, with △ AEF ≌ WSB, AF = EF = WS = BS = aesin45 ° = 22s sector AGD = s sector BDH = 14 π· ad2 = 14 π, s △ AEF = s △ WSB = 12af2 = 14, ≌ s shadow = 2 · s sector agd-2 · s △ AEF = π 2-12