Radius and Diameter worksheet - Free Printable

Problem Explanation:

The worksheet asks us to determine the radius and diameter of various circles. The relationship between the radius and diameter is fundamental:
- Diameter (d) = 2 × Radius (r)
- Radius (r) = Diameter (d) ÷ 2

We will solve each part step by step.

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Solution:

#### Part a:
- Given: Radius = 5 mm
- Diameter: \( d = 2 \times r = 2 \times 5 \, \text{mm} = 10 \, \text{mm} \)
- Answer:
- Radius = 5 mm
- Diameter = 10 mm

#### Part b:
- Given: Diameter = 12 cm
- Radius: \( r = \frac{d}{2} = \frac{12 \, \text{cm}}{2} = 6 \, \text{cm} \)
- Answer:
- Radius = 6 cm
- Diameter = 12 cm

#### Part c:
- Given: Radius = 9 m
- Diameter: \( d = 2 \times r = 2 \times 9 \, \text{m} = 18 \, \text{m} \)
- Answer:
- Radius = 9 m
- Diameter = 18 m

#### Part d:
- Given: Diameter = 16 km
- Radius: \( r = \frac{d}{2} = \frac{16 \, \text{km}}{2} = 8 \, \text{km} \)
- Answer:
- Radius = 8 km
- Diameter = 16 km

#### Part e:
- Given: Radius = 11 m
- Diameter: \( d = 2 \times r = 2 \times 11 \, \text{m} = 22 \, \text{m} \)
- Answer:
- Radius = 11 m
- Diameter = 22 m

#### Part f:
- Given: Diameter = 30 mm
- Radius: \( r = \frac{d}{2} = \frac{30 \, \text{mm}}{2} = 15 \, \text{mm} \)
- Answer:
- Radius = 15 mm
- Diameter = 30 mm

#### Part g:
- Given: Diameter = 26 km
- Radius: \( r = \frac{d}{2} = \frac{26 \, \text{km}}{2} = 13 \, \text{km} \)
- Answer:
- Radius = 13 km
- Diameter = 26 km

#### Part h:
- Given: Radius = 7 cm
- Diameter: \( d = 2 \times r = 2 \times 7 \, \text{cm} = 14 \, \text{cm} \)
- Answer:
- Radius = 7 cm
- Diameter = 14 cm

#### Part i:
- Given: Diameter = 18 km
- Radius: \( r = \frac{d}{2} = \frac{18 \, \text{km}}{2} = 9 \, \text{km} \)
- Answer:
- Radius = 9 km
- Diameter = 18 km

#### Part j:
- Given: Radius = 1 m
- Diameter: \( d = 2 \times r = 2 \times 1 \, \text{m} = 2 \, \text{m} \)
- Answer:
- Radius = 1 m
- Diameter = 2 m

#### Part k:
- Given: Radius = 17 cm
- Diameter: \( d = 2 \times r = 2 \times 17 \, \text{cm} = 34 \, \text{cm} \)
- Answer:
- Radius = 17 cm
- Diameter = 34 cm

#### Part l:
- Given: Diameter = 50 mm
- Radius: \( r = \frac{d}{2} = \frac{50 \, \text{mm}}{2} = 25 \, \text{mm} \)
- Answer:
- Radius = 25 mm
- Diameter = 50 mm

#### Part m:
- Given: The distance from the center of the pool to the edge is 3 meters (this is the radius).
- Diameter: \( d = 2 \times r = 2 \times 3 \, \text{m} = 6 \, \text{m} \)
- Answer: Diameter = 6 meters

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Final Answers:

\[
\boxed{
\begin{array}{ll}
\text{a.} & \text{Radius = 5 mm, Diameter = 10 mm} \\
\text{b.} & \text{Radius = 6 cm, Diameter = 12 cm} \\
\text{c.} & \text{Radius = 9 m, Diameter = 18 m} \\
\text{d.} & \text{Radius = 8 km, Diameter = 16 km} \\
\text{e.} & \text{Radius = 11 m, Diameter = 22 m} \\
\text{f.} & \text{Radius = 15 mm, Diameter = 30 mm} \\
\text{g.} & \text{Radius = 13 km, Diameter = 26 km} \\
\text{h.} & \text{Radius = 7 cm, Diameter = 14 cm} \\
\text{i.} & \text{Radius = 9 km, Diameter = 18 km} \\
\text{j.} & \text{Radius = 1 m, Diameter = 2 m} \\
\text{k.} & \text{Radius = 17 cm, Diameter = 34 cm} \\
\text{l.} & \text{Radius = 25 mm, Diameter = 50 mm} \\
\text{m.} & \text{Diameter = 6 meters}
\end{array}
}
\]