Calculate the circumference of circles with given radii and diameters, using pi approximately 22/7.

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ScanSolve AI Tutor · Accepted Answer

Here are the circumferences for all the circles:

The formula for the circumference of a circle is $C = 2\pi r$ (where $r$ is the radius) or $C = \pi d$ (where $d$ is the diameter). We will use $\pi \approx \frac{22}{7}$ .

Calculate the circumference for circles 1, 2, and 3.
1. Given radius $r = 21$ cm. $C = 2\pi r = 2 \times \frac{22}{7} \times 21 \text{ cm}$ $C = 2 \times 22 \times 3 \text{ cm}$ $C = \boxed{132 \text{ cm}}$
2. Given diameter $d = 28$ cm. $C = \pi d = \frac{22}{7} \times 28 \text{ cm}$ $C = 22 \times 4 \text{ cm}$ $C = \boxed{88 \text{ cm}}$
3. Given radius $r = 7$ cm. $C = 2\pi r = 2 \times \frac{22}{7} \times 7 \text{ cm}$ $C = 2 \times 22 \text{ cm}$ $C = \boxed{44 \text{ cm}}$
Calculate the circumference for circles 4, 5, and 6.
1. Given diameter $d = 15$ cm. $C = \pi d = \frac{22}{7} \times 15 \text{ cm}$ $C = \frac{330}{7} \text{ cm}$ $C = \boxed{47\frac{1}{7} \text{ cm}}$
2. Given radius $r = 11$ cm. $C = 2\pi r = 2 \times \frac{22}{7} \times 11 \text{ cm}$ $C = \frac{484}{7} \text{ cm}$ $C = \boxed{69\frac{1}{7} \text{ cm}}$
3. Given diameter $d = 49$ cm. $C = \pi d = \frac{22}{7} \times 49 \text{ cm}$ $C = 22 \times 7 \text{ cm}$ $C = \boxed{154 \text{ cm}}$

Calculate the circumference of circles with given radii and diameters, using pi approximately 22/7.

Step-by-step solution

Calculate the circumference for circles 1, 2, and 3.

Calculate the circumference for circles 4, 5, and 6.

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