Question
How to find the formula for the surface area of a circular table?
Answers
Answered by
GPT-4o mini
To find the formula for the surface area of a circular table, you need to consider the shape of the table's top. A circular table top is a flat disk, and the formula for the surface area \( A \) of a circle is given by:
\[
A = \pi r^2
\]
where:
- \( A \) is the surface area,
- \( r \) is the radius of the circle, and
- \( \pi \) (pi) is a mathematical constant approximately equal to 3.14159.
### Finding the Radius
1. **Measure the diameter of the circular table**: The diameter is the distance across the circle through its center.
2. **Calculate the radius**: The radius is half of the diameter:
\[
r = \frac{d}{2}
\]
where \( d \) is the diameter.
### Step-by-Step Calculation
1. **Measure** the diameter of the table (e.g., 1.2 meters).
2. **Calculate** the radius:
\[
r = \frac{1.2 \text{ m}}{2} = 0.6 \text{ m}
\]
3. **Plug the radius into the surface area formula**:
\[
A = \pi (0.6 \text{ m})^2 = \pi (0.36 \text{ m}^2) \approx 1.1319 \text{ m}^2
\]
So, the surface area of the circular table is approximately 1.1319 square meters.
### Conclusion
The formula for the surface area of a circular table is \( A = \pi r^2 \). You just need to know the radius (or diameter) of the table to calculate the area.
\[
A = \pi r^2
\]
where:
- \( A \) is the surface area,
- \( r \) is the radius of the circle, and
- \( \pi \) (pi) is a mathematical constant approximately equal to 3.14159.
### Finding the Radius
1. **Measure the diameter of the circular table**: The diameter is the distance across the circle through its center.
2. **Calculate the radius**: The radius is half of the diameter:
\[
r = \frac{d}{2}
\]
where \( d \) is the diameter.
### Step-by-Step Calculation
1. **Measure** the diameter of the table (e.g., 1.2 meters).
2. **Calculate** the radius:
\[
r = \frac{1.2 \text{ m}}{2} = 0.6 \text{ m}
\]
3. **Plug the radius into the surface area formula**:
\[
A = \pi (0.6 \text{ m})^2 = \pi (0.36 \text{ m}^2) \approx 1.1319 \text{ m}^2
\]
So, the surface area of the circular table is approximately 1.1319 square meters.
### Conclusion
The formula for the surface area of a circular table is \( A = \pi r^2 \). You just need to know the radius (or diameter) of the table to calculate the area.