Question

折叠长方形ABCD,使点B落到AD边的F点上,折痕为CE,已知AB=3,BC=5,则EF=_______

Answer 1

三减去二倍根号二

BC=FC=5=>FD=4=>AF=1=>AE=二倍根号二=>BE=三减去二倍根号二=EF