Question:
In a circle, if the radius is 7 units, what is the circumference? (Use \(\pi \approx 3.14\))
In a circle, if the radius is 7 units, what is the circumference? (Use \(\pi \approx 3.14\))
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A common mistake is to confuse the formula for circumference (\(C = 2 \pi r\)) with the formula for area (\(A = \pi r^2\)). Remember that circumference is a length (units) while area is a surface (square units).
Updated On: Oct 4, 2025
- 21.98 units
- 43.96 units
- 14 units
- 49 units
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The Correct Option is B
Solution and Explanation
Step 1: Understanding the Concept
The circumference of a circle is the distance around its edge. It is calculated using the circle's radius or diameter.
Step 2: Key Formula or Approach
The formula for the circumference (C) of a circle is:
\[ C = 2 \pi r \] where 'r' is the radius and \(\pi\) (pi) is a mathematical constant, approximately 3.14.
Step 3: Detailed Explanation
We are given:
Radius (r) = 7 units
\(\pi \approx 3.14\)
Substitute these values into the circumference formula:
\[ C = 2 \times 3.14 \times 7 \] \[ C = 6.28 \times 7 \] \[ C = 43.96 \text{ units} \] Step 4: Final Answer
The circumference of the circle is 43.96 units.
The circumference of a circle is the distance around its edge. It is calculated using the circle's radius or diameter.
Step 2: Key Formula or Approach
The formula for the circumference (C) of a circle is:
\[ C = 2 \pi r \] where 'r' is the radius and \(\pi\) (pi) is a mathematical constant, approximately 3.14.
Step 3: Detailed Explanation
We are given:
Radius (r) = 7 units
\(\pi \approx 3.14\)
Substitute these values into the circumference formula:
\[ C = 2 \times 3.14 \times 7 \] \[ C = 6.28 \times 7 \] \[ C = 43.96 \text{ units} \] Step 4: Final Answer
The circumference of the circle is 43.96 units.
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