Answer:
28 ft²
Explanation:
You want the area of a triangle with a base of 7' and a height of 8'.
Area formula
The formula for the area of a triangle is ...
A = 1/2bh
where b is the base of the triangle, and h is the height perpendicular to the base.
Here, it is convenient to use the side marked 7' as the base of the triangle. The distance marked 8' is the perpendicular distance from the base to the top of the triangle. So, the area is ...
A = 1/2(7 ft)(8 ft) = 28 ft²
The area of the triangle is 28 square feet.
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Additional comment
As you can see, the vertex opposite the base does not need to lie above the base segment. All that matters is the perpendicular distance from that vertex to the base line.