∵A`E⊥AC ∴ ∠AED=45
D is the midpoint of AB.
∴DG = ge = BC/2 = 3 AE = a ` e = ag+ge = 4+3 = 7
a ` f = a ` e-BC = 1 FB = EC = 1
A`B= √2
The shaded part in the above figure consists of eight green figures, the area of which is1/4, the area of a circle with a radius of 16÷2-1/2, a