Question

What is the area of a pizza that has a diameter 18 inches

Answer 1

A = 81π in²

A ≈ 254.34 in²

Explanation:

Area of a circle is:

`A = \pi r^2\\\rule{150}{0.5}\\r \text{ - radius}`

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The diameter is double the radius. T

his means that the radius is half the diameter.

18in./2 = 9in

The radius is 9 in.

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`A = \pi r^2\\\rule{150}{0.5}\\A = \pi (9)^2\\\\A = \pi 81\\\\\boxed{A = 81\pi \text{ in.}^2}\\\\\textbf{or}\\\\A \approx 81 * 3.14\\\\\boxed{A \approx 254.34 \text{ in.}^2}`

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Hope this helps.

Answer 2

Area of a circle = πr^2

18 inches = 9 inches (radius)

A = π×9^2

A = 81π inches^2

Or...

A = 81×π

A = 254.5 inches^2 (1 dp)