Question

Find the area of AABC having vertices A(1, -3), B(4, -3) and C(-9, 7).​

Answer 1

Answer:

△ABC has vertices A(4,2),B(3,9) and C(10,10).

The area of a triangle formed by joining the points (x

1

,y

1

),(x

2

,y

2

),(x

3

,y

3

) is

2

1

∣x

1

(y

2

−y

3

)+x

2

(y

3

−y

1

)+x

3

(y

1

−y

2

)∣

∴ Area of △ABC

2

1

∣4(9−10)+3(10−2)+10(2−9)∣

=

2

1

∣−4+24−70∣=

2

50

=25

Hence, area of triangle ABC is 25.