Question

If a = 31, what is the circumference of the circle? (Round to one decimal place.)

Answer 1

Answer:

The circumference is 194.78, but it's 194.8 when rounded to the nearest tenth.

The area is 3019.1.

Step-by-step explanation:

To find these values, all you have to do is use these formulas.

Area = πr2.

Circumference = 2πr.

Since you already know what r (radius, but it's marked as a on the drawing) is, you can simply plug r (31) into the formulas.

First let's do area.

Area = π(31)²

Do (31)² first before doing anything with π.

(31)² = 961

Now you have:

Area = π(961)

π · 961 = 3019.1

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Now for the circumference. Put 31 in place of "r".

C = 2π(31)

Do π(31)

π · 31 = 97.3893722613, but you can shorten that big number if you want, too.

Now you have:

C = 2(97.3893722613)

2 · 97.3893722613 = 194.8

Answer 2

circumference is 62pi which equals 194.8

area is 31^2pi which equals 3109.1