We get
[tex]AC^2 + BC^2 = 11^2[/tex]
[tex]AD^2 + CD^2 = AC^2[/tex]
Adding equations,
[tex]AC^2 + BC^2 + AD^2 + CD^2= 11^2 + AC^2[/tex]
[tex]BC^2 + AD^2 + CD^2= 11^2[/tex]
For the total sum of squares we need to add [tex]AB^2[/tex]
[tex]AB^2 + BC^2 +AD^2 + CD^2= 11^2 + 11^2 = 242[/tex]
