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[-4x + 4]
= -2x + 2
The given points are collinear if and only if area = 0
-2x + 2 = 0
2x = 2
x = 1
Hence the required value of x = 1

Exa:6 Find the area of quadrilateral ABCD whose vertices are A (-4,-2), B (-3,-5), C (3,-2) and D (2, 3).

If ABCD is a quadrilateral then we get the two triangles by joining A and C. To find the area of Quadrilateral ABCD we
can find the area of ∆ ABC and ∆ ADC and then add them.

Exa7- The coordinates of the vertices of ABC are A(4, 1), B (-3,2) and C (0, k). Given
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that the area of ABC is 12 unit , find the value of k.
Sol. The area of ABC formed by the given points A(4, 1), B(-3, 2) and C(0, k)

Here, x 1 = 4, y 1 = 1, x 2 = - 3, y 2 = 2, x 3 = 0, y 3 = k

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