[X1 = 2 , Y1 = 3 ; X2 = 4 , Y2 = 3 ; X3 = 0 , Y3 = -2; X1 Y1 1 the area of the triangle is 0,5× det(ABC)= 0,5 × X2 Y2 1 X3 Y3 1 det(ABC) = 0,5 × |-10| = 5 unit²