Question

part c: guided practice

1. what is the radius of a circle?
2. if the diameter of the circle to the right is 4 cm, what would be its radius in cm?

image: a circle with a horizontal line labeled \diameter\ (passing through the center) and a shorter line from center to edge labeled
adius\

Explanation:

Question 1

The radius of a circle is defined as the distance from the center of the circle to any point on its circumference. It is also half of the diameter of the circle, i.e., if \(d\) is the diameter, then the radius \(r=\frac{d}{2}\).

Step1: Recall the relationship between diameter and radius

The formula relating diameter (\(d\)) and radius (\(r\)) of a circle is \(r = \frac{d}{2}\).

Step2: Substitute the given diameter value

Given that the diameter \(d = 4\space\text{cm}\), substitute this value into the formula: \(r=\frac{4}{2}\).

Step3: Calculate the radius

\(\frac{4}{2}=2\).

Answer:

The radius of a circle is the distance from the center of the circle to any point on its circumference (or half of the circle's diameter).

Question 2