Let's solve the problem step by step.
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Understanding the Concepts:
-
Radius (r): The distance from the center of a circle to any point on its edge.
-
Diameter (d): The distance across the circle passing through the center. It is
twice the radius.
- So,
d = 2 × r, or
r = d ÷ 2
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We’ll go through each circle and calculate the
radius and
diameter based on the given value.
---
a.
- Given: Radius =
8 mm
- Diameter = 2 × 8 =
16 mm
-
✔ radius = 8 mm,
diameter = 16 mm
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b.
- Given: Diameter =
10 cm
- Radius = 10 ÷ 2 =
5 cm
-
✔ radius = 5 cm,
diameter = 10 cm
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c.
- Given: Radius =
3 in
- Diameter = 2 × 3 =
6 in
-
✔ radius = 3 in,
diameter = 6 in
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d.
- Given: Diameter =
14 km
- Radius = 14 ÷ 2 =
7 km
-
✔ radius = 7 km,
diameter = 14 km
---
e.
- Given: Radius =
4.1 m
- Diameter = 2 × 4.1 =
8.2 m
-
✔ radius = 4.1 m,
diameter = 8.2 m
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f.
- Given: Diameter =
28 mm
- Radius = 28 ÷ 2 =
14 mm
-
✔ radius = 14 mm,
diameter = 28 mm
---
g.
- Given: Diameter =
26 cm
- Radius = 26 ÷ 2 =
13 cm
-
✔ radius = 13 cm,
diameter = 26 cm
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h.
- Given: Radius =
2 cm
- Diameter = 2 × 2 =
4 cm
-
✔ radius = 2 cm,
diameter = 4 cm
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i.
- Given: Diameter =
18 km
- Radius = 18 ÷ 2 =
9 km
-
✔ radius = 9 km,
diameter = 18 km
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j.
- Given: Radius =
1 m
- Diameter = 2 × 1 =
2 m
-
✔ radius = 1 m,
diameter = 2 m
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k.
- Given: Radius =
4.5 cm
- Diameter = 2 × 4.5 =
9 cm
-
✔ radius = 4.5 cm,
diameter = 9 cm
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l.
- Given: Diameter =
60 mm
- Radius = 60 ÷ 2 =
30 mm
-
✔ radius = 30 mm,
diameter = 60 mm
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m. Word Problem:
> John has a round swimming pool. The distance from the center of the pool to the edge is 3 meters. What is the diameter of John’s pool?
- The distance from the center to the edge is the
radius →
r = 3 meters
- Diameter = 2 × radius = 2 × 3 =
6 meters
-
✔ Answer: 6 meters
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✔ Final Answers:
| Letter | Radius | Diameter |
|--------|--------------|---------------|
| a | 8 mm | 16 mm |
| b | 5 cm | 10 cm |
| c | 3 in | 6 in |
| d | 7 km | 14 km |
| e | 4.1 m | 8.2 m |
| f | 14 mm | 28 mm |
| g | 13 cm | 26 cm |
| h | 2 cm | 4 cm |
| i | 9 km | 18 km |
| j | 1 m | 2 m |
| k | 4.5 cm | 9 cm |
| l | 30 mm | 60 mm |
| m | — |
6 meters |
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✔ Answer to part m: 6 meters
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Parent Tip: Review the logic above to help your child master the concept of radius and diameter worksheet answers.
