Answer:
52.5 ft^2
Explanation:
7ft * 12ft = 84
84 / 2 = 42
7ft * 3ft = 21
21 = 2 = 10.5
42 + 10.5 = 52.5
To solve for a right sided triangle simply multiply the sides as if you were solving a square and then divide it by two. If you split these into two right sided triangles you can just solve each one and then add them