2017中考数学真题

如图:连接a' b?打造BF⊥A`E DG⊥AC

∵A`E⊥AC ∴ ∠AED=45

D是AB的中点

∴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