Using integration, find the area of the region bounded by the triangle whose vertices are `(-1, 2), (1, 5) and (3, 4)`.

Explanation

Equations of AB,BC and AC are
`y = 1/2 (3x +7 ), y= 1/2 (11-x)`
and `y =1/2(3x + 7 ),y =1/2(11-x)`
and `y = 1/2 (x+5)` respectively
`therefore Delta =1/2underset(-1)overset(1)int (3x+7)dx + 1/2underset(1)overset(3)int (11-x)dx -1/2underset(1)overset(3)int (x+5)dx`