Question: A circular pool has a safety fence around it. There is a gate in the fence which is 150 cm wide.
20 m
gate
150 cm
What is the length of the fence not including the gate?
m
Use \pi = 3
1. **State the problem:** We need to find the length of the fence around a circular pool excluding the gate width.
2. **Given data:**
- Diameter of the pool $d = 20$ m
- Gate width $= 150$ cm $= \frac{150}{100} = 1.5$ m
- Use $\pi = 3$
3. **Formula for circumference of a circle:**
$$ C = \pi d $$
4. **Calculate the total circumference:**
$$ C = 3 \times 20 = 60 \text{ m} $$
5. **Subtract the gate width from the total circumference to get the fence length:**
$$ \text{Fence length} = C - \text{gate width} = 60 - 1.5 = 58.5 \text{ m} $$
6. **Final answer:**
The length of the fence not including the gate is **58.5 m**.