Answer:
a. 314.2 in²
b. 36 m²
c. 60 m²
Step-by-step explanation:
The areas of these plane figures can be found by substituting the given dimensions into the area formula.
a.
The area of a circle can be found from its diameter to be ...
A = (π/4)d²
A = (π/4)(20 in)² = 100π in² ≈ 314.2 in²
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b.
The area of a parallelogram can be found as ...
A = bh
A = (9 m)(4 m) = 36 m²
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c.
The area of a triangle can be found from ...
A = 1/2bh
A = 1/2(15 m)(8 m) = 60 m²
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Additional comment
A triangle with sides 17 and 15 and height 8 cannot be obtuse. It is a right triangle. (Those side lengths are a Pythagorean triple.)
