Question

7) The area of triangle ABC whose vertices are A(1,2) ; B(2,3) ;C(-1, 4) is, a) 1 b) 2 c) 3 d) 6​

Answer 1

Answer:

Correct option is B)

We know that the area of the triangle whose vertices are (x

1

,y

1

),(x

2

,y

2

), and (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 =

2

1

[1(1)+7(1)+12(−2)]=−8, but area can not be negative

Hence, area = 8 square units.