Answer:
280.2 m²
Explanation:
The height of the triangle is found using the Pythagorean theorem.
a² +b² = c²
13² +b² = 20²
b² = 20² -13² = 400 -169 = 231
b = √231 ≈ 15.199 . . . . meters
The area of the figure is 1/4 the area of a circle with radius √231 together with the area of the triangle with base 13 and height √231.
Triangle Area = 1/2bh
= 1/2(13)(15.199) ≈ 98.791 . . . . square meters
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The area of the 1/4 circle is ...
Sector Area = (1/4)πr² = 1/4π(√231)² = (231π)/4 ≈ 181.427 . . . . square meters
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The figure area is the sum of the triangle and quarter circle areas:
figure area = 98.791 m² +181.427 m² ≈ 280.2 m²
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Additional comment
If you use 3.14 for π, then the total will be 280.1 m².