Question

Please hurry, this is past due.Don’t answer if you don’t know.

Answer 1

31.4cm

Explanation:

Formula for circumference of a circle:

`C = 2\pi r`

The radius of a circle is half of the diameter:

10/2 = 5

Plug in the values using 3.14 for pi:

C = 2(3.14)(5)

C = 31.4cm

Answer 2

D. 70.39

Explanation:

This is not a good question, but I will show you how to get the answer I chose.

Area = (pi)(r)^2

394.38 = (3.14)(r)^2

divide both sides by 3.14

125.598726 = r^2

take the square root of both sides

r = 11.207083...

rounded is 11.21

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Circumference = (2)(pi)(r)

C = (2)(3.14)(11.207083)

C = 70.38

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Here's why it's a bad question:

If the diameter is 10, the radius is half of that, = 5

Area = (pi)(r)^2

Area = (3.14)(5)^2

A = (3.14)(25)

A = 78.5

So the question says the diameter is 10, but if that's true, the area cannot be 394.38

Also, the circumference can be calculated as (pi)(diameter), so 3.14 x 10 = 31.40, which is not an answer option.