bonjour
[AB]² = ( 3 + 2 )² + ( 3 - 1 )² = 5 ² + 2 ² = 25 + 4 = 29
[BC]² = ( 4 - 3 )² + ( 0 - 3 )² = 1² + ( -3 )² = 1 + 9 = 10
[ CD]² = ( - 1 - 4 )² + ( - 2 - 0 )² = ( - 5 )² + ( -2 )² = 25 + 4 = 29
{AD] ² = ( - 1 + 2 )² + ( - 2 - 1 )² = 1 ² + ( - 3 )² = 1 + 9 = 10