Question

What is the radius of a circle with circumference C = 20 CM?

Answer 1

r≈3.18cm

1) Let's begin by reminding ourselves of the formula of the Circumference:

C=2\pi rC=2πr

2) Note that for this question, we'll round π as simply 3.14 so let's plug it into that formula with the Circumference:

\begin{gathered}\begin{gathered} 20=2(3.14)r \\ 2\mleft(3.14\mright)r=20 \\ 6.28r=20 \\ \frac{6.28r}{6.28}=\frac{20}{6.28} \\ r\approx3.18cm \end{gathered}\end{gathered}

20=2(3.14)r

2\mleft(3.14\mright)r=20

6.28r=20

6.28

6.28r

=

6.28

20

r≈3.18cm

Answer 2

`r\approx3.18cm`

1) Let's begin by reminding ourselves of the formula of the Circumference:

`C=2\pi r`

2) Note that for this question, we'll round π as simply 3.14 so let's plug it into that formula with the Circumference:

`\begin{gathered} 20=2(3.14)r \\ 2\mleft(3.14\mright)r=20 \\ 6.28r=20 \\ (6.28r)/(6.28)=(20)/(6.28) \\ r\approx3.18cm \end{gathered}`

Thus, this is the answer.