Question

Find the area and circumference of a circle with a diameter of 30 ft
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Answer 1

`\large\boxed{C=30\pi\ ft,\ A=225\pi\ ft^2}`

Explanation:

The formula of a circumference of a circle:

`C=d\pi`

d - diameter

The formula of an area of a circle:

`A=\pi r^2`

r - radius

We have the diameter d = 30 ft. We know d= 2r.

Therefore r = 30 : 2 = 15 ft.

Substitute:

`C=30\pi\ ft\\\\A=\pi(15^2)=225\pi\ ft^2`