Question

1. calculate the circumference and area of a circle with the given measure. use 3.14 for π. a. radius = 3 cm b. diameter = 4 ft module 1 • topic 3 • skills practice

Explanation:

Step1: Recall circle - formulas

The formula for the circumference of a circle is $C = 2\pi r$ or $C=\pi d$, and the formula for the area of a circle is $A=\pi r^{2}$, where $r$ is the radius and $d$ is the diameter.

Step2: Calculate for part a (radius $r = 3$ cm)

Circumference

$C = 2\pi r=2\times3.14\times3 = 18.84$ cm

Area

$A=\pi r^{2}=3.14\times3^{2}=3.14\times9 = 28.26$ cm²

Step3: Calculate for part b (diameter $d = 4$ ft)

First, find the radius $r=\frac{d}{2}=\frac{4}{2}=2$ ft

Circumference

$C=\pi d=3.14\times4 = 12.56$ ft

Area

$A=\pi r^{2}=3.14\times2^{2}=3.14\times4 = 12.56$ ft²

Answer:

a. Circumference: 18.84 cm, Area: 28.26 cm²
b. Circumference: 12.56 ft, Area: 12.56 ft²