Answer:
Explanation:
Remark
The plan is to find the third side. It and the 9 foot side form a right angle. The base is given as 9 feet. The third sid will be the altitutude. The formula is Area = 1/2 * Base * third side.
Formulas
c^2 = b^2 + a^2
Area = 1/2 b * a
Givens
c = 13 feet
a = ?
b = 9 feet.
Answer: 42.2 square feet.
Solution
c^2 = b^2 + a^2
13^2 = 9^2 + a^2
169 = 81 + a^2 Subtract 81 from both sides.
169 - 81 =81 - 81 + a^2 Combine
88 = a^2 Take the square root of both sides
√a^2=√88
a = 9.381
Area = 1/2 * 9 * 9.381
Area = 42.21
Rounded to the nearest 1/10 Area = 42.2