Question

radius =
diameter =
area =
circumference =
30.4 in

Explanation:

Step1: Recall radius - diameter relationship

The diameter \(d\) of a circle is given as \(d = 30.4\) in. The radius \(r\) of a circle is half of the diameter, so \(r=\frac{d}{2}\).
\[r=\frac{30.4}{2}=15.2\text{ in}\]

Step2: Calculate the area of the circle

The formula for the area \(A\) of a circle is \(A=\pi r^{2}\). Substitute \(r = 15.2\) in.
\[A=\pi\times(15.2)^{2}=\pi\times231.04\approx 3.14\times231.04 = 725.4656\text{ in}^2\]

Step3: Calculate the circumference of the circle

The formula for the circumference \(C\) of a circle is \(C = 2\pi r\) or \(C=\pi d\). Using \(d = 30.4\) in, we have \(C=\pi\times30.4\approx3.14\times30.4 = 95.456\text{ in}\)

Answer:

Radius = \(15.2\) in
Diameter = \(30.4\) in
Area \(\approx725.47\text{ in}^2\)
Circumference \(\approx95.46\text{ in}\)