Answer:
45 units^2
Step-by-step explanation:
Think of this polygon as being the combination of a rectangle and a triangle. The rectangle is at the bottom. It has length 9 and width 2.
The triangle is above it. Its base is also 9 like the rectangle's length. The height of the triangle is the segment from point (2, -1) to (2, 4). The length of the height is 6.
Now use the area formulas for a rectangle and a triangle to find the two areas and add them,
Rectangle: A = LW
Triangle: A = bh/2
Total area = LW + bh/2
Total area = 9 * 2 + 9 * 6/2
Total area = 18 + 54/2
Total area = 18 + 27
Total area = 45 units^2
