Question

find the circumference and area of each circle. use 3.14 for \\( \pi \\) and round your answer to the nearest hundredth. (two decimal places)
a.
\\( c = \\) \\( \text{in.} \\)
\\( a = \\) \\( \text{in}^2 \\)
b.
\\( c = \\) \\( \text{cm} \\)
\\( a = \\) \\( \text{cm}^2 \\)
c.
\\( c = \\) \\( \text{cm} \\)
\\( a = \\) \\( \text{cm}^2 \\)

Explanation:

Part a: Circle with diameter 12 in

Step1: Calculate radius

$r = \frac{12}{2} = 6$ in

Step2: Find circumference

$C = \pi d = 3.14 \times 12 = 37.68$ in

Step3: Find area

$A = \pi r^2 = 3.14 \times 6^2 = 3.14 \times 36 = 113.04$ in²

Part b: Circle with diameter 22 cm

Step1: Calculate radius

$r = \frac{22}{2} = 11$ cm

Step2: Find circumference

$C = \pi d = 3.14 \times 22 = 69.08$ cm

Step3: Find area

$A = \pi r^2 = 3.14 \times 11^2 = 3.14 \times 121 = 379.94$ cm²

Part c: Circle with radius 12 cm

Step1: Find circumference

$C = 2\pi r = 2 \times 3.14 \times 12 = 75.36$ cm

Step2: Find area

$A = \pi r^2 = 3.14 \times 12^2 = 3.14 \times 144 = 452.16$ cm²

Answer:

a. $C = 37.68$ in, $A = 113.04$ in²
b. $C = 69.08$ cm, $A = 379.94$ cm²
c. $C = 75.36$ cm, $A = 452.16$ cm²