bonsoir
(AB)²= ( 2 - 6 ) ² + ( - 3 - 5 )² = ( - 4 )² + ( - 8 )² = 16 + 64 = 80
( BC)² = ( - 4 - 2 )² + ( 0 + 3 )² = ( - 6 )² + 3 ² = 36 + 9 = 45
( AC)² = ( - 4 - 6 )² + ( 0 - 5 )² = ( - 10 )² + ( - 5 )² = 100 + 25 = 125
80 + 45 = 125
ABC est rectangle
Périmètre = √80 + √ 45 + √ 125 = 4 √5 + 3 √5 + 5 √5 = 12 √5
Aire = ( √80 x √45 ) / 2 = 60 /2 = 30
