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Find the area of the triangle whose vertices are: `(-2,-3),(3,2),(-1,-8)`

Answer» Here, `(x_(1) =-2, y_(1) =-3), (x_(2) =3, y_(2) =2) " and " (x_(3) =-1, y_(3) =-8)`
`therefore (1)/(2) |[x_(1), y_(1), 1],[x_(2), y_(2), 1],[x_(3), y_(3), 1]| =(1)/(2) * |[-2, -3, 1],[3, 2, 1],[-1, -8, 1]|`
`=(1)/(2) * |[-2, -3, 1],[5, 5, 0],[1, -5, 0]| [R_(2) to (R_(2) -R_(1)) " and" R_(3) to (R_(3) -R_(1))]`
` =(1)/(2) *1* |[5, 5], [1, -5]| = (1)/(2) xx (-25 -5) = -15`
Hence, ar `(triangleABC) =|-15| =15` square units.


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