panjang AE adalah...

AB = BC
AC^2 = AB^2 + BC^2
AC^2 = 2^2 + 2^2
AC^2 = 4 + 4
AC^2 = 8
AC = akar 8 cm

AC = CD
AD^2 = AC^2 + CD^2
AD^2 = (akar 8)^2 + (akar 8)^2
AD^2 = 8 + 8
AD^2 = 16
AD = akar 16
= 4 cm

AD = DE
AE^2 = AD^2 + DE^2
AE^2 = 4^2 + 4^2
AE^2 = 16 + 16
AE^2 = 32
AE = akar 32
= akar 4 x 4 x 2
= 4 akar 2 cm

semoga membantu:)