Question

Find the area of x .if the area of the triangle formed by (-2,2),(-1,-3) ,(x,0)is 3sq.units

Answer 1

area of ∆ =

1/2{ x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2) }

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we are given three vertices of a triangle,

• A(-2,2)
• B(-1,-3)
• C(x,0)

and it's area,

• 3 sq. units

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substituting values in the formula,

area =

1/2 {-2(-3-0) + (-1)(0-2) + x(2-(-3) } = 3

1/2 { -2(-3-0) -1(2) + x(2+3) }= 3

1/2 { 6 - 2 + 2x + 3x } = 3

{ 4 + 5x } = 3 x 2

4 + 5x = 6

5x = 6 - 4

5x = 2

x = 2/5