Question

find the area of the triangle whose vertices are(4, 2), (4,5)and (-2,2)​

Answer 1

Area of triangle = 1/2 [ x1(y2 -y3) + x2(y3-y1) + x3(y1-y2)

x1= 4; x2 = 4; x3= -2

y1= 2; y2 = 5 ; y3= 2

1/2 [ 4(5-2) + 4(2-2) +(-2)(2-5)]

= 1/2 [4(3) + 4(0) -2(-3)]

= 1/2 [ 12+0+6]

= 1/2[18]

=9

Answer 2

(4,2)=X1,y1

(4,5)=X2,y2

(-2,2)=x3,y3

1/2 {X1(y3-y2)+X2(y3-y1)+x3(y3-y2)

1/2{4(5-2)+4(2-2)+(-2)(2-5)

1/2{4(3)+4(0)-2(-3)}

1/2{12+0+6}

1/2{18}

18/2

=9