bonjour
[ RS]² = ( - 2 + 3 )² + ( 1 + 1 )² = 1² + 2 ² = 5
[ ST]² = ( - 4 + 3 )² + ( 0 + 1 )² = ( - 1 )² + 1 ² = 2
[RT]² = ( - 4 + 3 )² + ( 0 + 1 )² = ( - 1 )² + 1 ² = 2
{AB]² = ( 2.3 + 2.5 )² + ( - 2.4 - 1.6 )² = 4.8² + ( - 4 )² = 39.04
{AC]² = ( 4 +2 .5)² + ( - 0.36 - 1.6 )² = 6.5² + ( - 1.96 )² = 46.0916
[ BC] ² = ( 4 - 2.3 )² + (- 0.36 + 2.4 )² = 1.7 ² + 2.04 ² = 7.0516
7.0516 + 39.04 = 46.0916
donc il est rectangle
