Answer:
30 square units
Step-by-step explanation:
We know that the area of a triangle is equal to half of the product between the base and the height.
In this case, we can see that one of the sides of the triangle is parallel to the x-axis, then we can define:
Base = difference between the two extreme x-values
In this case, the extremes (the point at the left and the point and the right) are:
(-5, 3) and (7, 3)
The difference between the x-values is:
D = (7 - (-5)) = 7 + 5 = 12
Then the base is 12 units long.
For the height, we can find the difference in the y-value between the lowest point and the highest one.
In this case, we have two points at the same height (both with y-value = 3)
and the top point is (4, 8)
The difference in the y-value is:
D = (8 - 3) = 5
Then the height is 5 units.
Now that we know the height and the base of the triangle, the area is:
A = (5 units)*(12 units)/2 = 30 square units.
