AB = √(xb - xa)² + (yb - ya)²

AB = √ (2 - 5)² + (-1 - 3) ²

AB = √ 3² + (-4)²

AB = √ 9+16

AB = √25

AB = 5

AC = √ (xc - xa)² + (yc - ya)²

AC = √ ( 0-5)² + ( 3-3)²

AC = √ 5² + 0

AC = √25

AC = 5

BC = √ ( xc - xb)² + ( yc - ya)²

BC = √ (0 - 2)² + (3+1)²

BC = √ (-2)² + 4²

BC = √ 4 + 16

BC = √20

BC = 4

2. le triangle ABC est un triangle isocèle

voilà (✿^‿^)