Question

Determine the value of x' for which the area of the
triangle formed by joining the points (x, 4), (0, 8) and
1
(-1, 3) will be 4 1/2square units. ​

Answer 1

If(x,y),(x

2

,y

2

) & (x

3

,y

3

) are

vertices of a triangle then the

area of a triangle is given by

=

2

1

[x

1

(y

2

−y

3

)+x

2

(y

3

−y

1

)+x

3

(y

2

−y

2

)]

given pts.

A(a,2a), B(-2,6) & C(3,1)

Area of △ABC=10 sq.units

⇒

2

1

[a(6−1)+(−2)(1−2a)+3(2a−6)]=10 sq.units

⇒6a−6−2+4a+6a−18=20

⇒16a−26=20

⇒16a=46

⇒a=

16

46

a=

8

23