Question

1. the circumference of a circle is 28.26 cm. what is the radius?

$c = 2\pi r$

Explanation:

Step1: Recall the formula for the circumference of a circle

The formula for the circumference \( C \) of a circle is \( C = 2\pi r \), where \( r \) is the radius and \( \pi \) is approximately \( 3.14 \). We are given \( C = 28.26 \) cm and we need to find \( r \).

Step2: Rearrange the formula to solve for \( r \)

From \( C = 2\pi r \), we can solve for \( r \) by dividing both sides of the equation by \( 2\pi \). So, \( r=\frac{C}{2\pi} \).

Step3: Substitute the given values into the formula

We know \( C = 28.26 \) cm and \( \pi\approx3.14 \). Substituting these values into the formula for \( r \), we get:
\( r=\frac{28.26}{2\times3.14} \)

Step4: Perform the calculations

First, calculate the denominator: \( 2\times3.14 = 6.28 \)
Then, perform the division: \( r=\frac{28.26}{6.28}=4.5 \)

Answer:

The radius of the circle is \( 4.5 \) cm.