Let's solve the problem step by step.
We are asked to
calculate the circumference of each circle. The formula for the
circumference (C) of a circle is:
$$
C = \pi \times d
$$
or
$$
C = 2\pi \times r
$$
Where:
- $ d $ is the
diameter
- $ r $ is the
radius
- $ \pi \approx 3.14 $
In this worksheet, all given values are
diameters, so we'll use:
$$
C = \pi \times d
$$
We’ll use $ \pi \approx 3.14 $ for calculations.
---
1) Diameter = 0.4 in
$$
C = \pi \times 0.4 = 3.14 \times 0.4 = 1.256 \text{ in}
$$
✔ Answer: 1.256 in
---
2) Diameter = 0.9 ft
$$
C = \pi \times 0.9 = 3.14 \times 0.9 = 2.826 \text{ ft}
$$
✔ Answer: 2.826 ft
---
3) Diameter = 0.8 in
$$
C = \pi \times 0.8 = 3.14 \times 0.8 = 2.512 \text{ in}
$$
✔ Answer: 2.512 in
---
4) Diameter = 0.5 yd
$$
C = \pi \times 0.5 = 3.14 \times 0.5 = 1.57 \text{ yd}
$$
✔ Answer: 1.57 yd
---
5) Diameter = 1.4 ft
$$
C = \pi \times 1.4 = 3.14 \times 1.4 = 4.396 \text{ ft}
$$
✔ Answer: 4.396 ft
---
6) Diameter = 0.1 in
$$
C = \pi \times 0.1 = 3.14 \times 0.1 = 0.314 \text{ in}
$$
✔ Answer: 0.314 in
---
✔ Final Answers:
1)
1.256 in
2)
2.826 ft
3)
2.512 in
4)
1.57 yd
5)
4.396 ft
6)
0.314 in
> 📝
Note: You can round answers to two decimal places if needed:
> - 1.26 in, 2.83 ft, 2.51 in, 1.57 yd, 4.40 ft, 0.31 in
But since the original measurements have one or two decimal places, using three decimals is acceptable for accuracy.
Let me know if you'd like the answers rounded!
Parent Tip: Review the logic above to help your child master the concept of diameter and radius worksheet.
