Answer: 12 unit^2
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working:
area of triangle = base x height
to find the base:
4 - (-2)
= 4 + 2
= 6
to find the height:
5 - 1
= 4
to find the area fo the triangle:
4 x 6 x 0.5
= 12
I think you should know how I found the base but for the height, picture a perpendicular line going down to the bottom of the triangle, it will be touching (1,1). Therefore, I used 5 from (1,5) minus 1 from (1,1)