Question

Find the area of the triangle whose vertices are (-3, -5) , (3, -2) and (2 , 3).(a) 18.5,(b) 8. 5 (c) 16.5 , (d) 12.5 .

Answer 1

Answer:

Given,

A=(-3, -5)

B=(3, -2)

C=(2, 3)

where, x1= -3, x2= 3, x3= 2

and y1 = -5, y2= -2, y3 = 3

Now, using triangle's formula ( from coordinate geometry)

Area of triangle ABC = 1/2 [ x1 (y2-y3) + x2 (y3-y1) + x3 ( y1-y2) ]

=1/2 [ (-3) (-2-3) + 3 (3-(-5)) + 2 (-5-(-2)) ]

=1/2 [ (-3) (-5) + 3( 8) +2 (-3) ]

=1/2 [ (-15) +24 + (-6) ]

=1/2 [ 3]

= 3/2

= 1.5

therefore the area of the triangle is 1.5 unit ².