假设AD=1则AB=根号2
AC=根号下AB方+AD方=根号3
AC*DE=AB*DC DC=AB
DE=根号6/3=BF
CF=根号下BC方-BF方=根号3/3=AE
EF=AC-AE-CF=根号3/3
DEBF面积=DE*EF=根号6/3 * 根号3/3=根号2/3
ABCD面积=AB*BC=根号2
DEBF:ABCD=1/3
假设AD=1则AB=根号2
AC=根号下AB方+AD方=根号3
AC*DE=AB*DC DC=AB
DE=根号6/3=BF
CF=根号下BC方-BF方=根号3/3=AE
EF=AC-AE-CF=根号3/3
DEBF面积=DE*EF=根号6/3 * 根号3/3=根号2/3
ABCD面积=AB*BC=根号2
DEBF:ABCD=1/3