bonjour
AB = ( 12 - 7 )² + ( - 1 - 4)² = 5² + ( - 5 )² = 25 + 25 = 50
BC = ( 9 - 12 )² + ( - 4 + 1 )² = ( - 3)² + ( - 3 )² = 9 + 9 = 18
CD = ( 4 - 9)² + ( 1 + 4 )² = ( - 5 )² + 5 ² = 25 + 25 = 50
Ad = ( 4 - 7 )² + ( 1 - 4 )² = ( - 3 )² + ( - 3)² = 9 + 9 = 18
ABCD est une rectangle