Questions: Find the circumference of a circle if the area is 300 square centimeters.
A) 61.38 cm
B) 56.25 cm
C) 84.74 cm
D) 9.77 cm
Transcript text: Find the circumference of a circle if the area is 300 square centimeters.
A) 61.38 cm
B) 56.25 cm
C) 84.74 cm
D) 9.77 cm
Solution
Solution Steps
To find the circumference of a circle given its area, we can use the following steps:
Use the formula for the area of a circle, \( A = \pi r^2 \), to solve for the radius \( r \).
Once the radius is found, use the formula for the circumference of a circle, \( C = 2 \pi r \), to find the circumference.
Step 1: Calculate the Radius from the Area
Given the area of the circle \( A = 300 \) square centimeters, we use the formula for the area of a circle:
\[ A = \pi r^2 \]
Solving for the radius \( r \):
\[ r = \sqrt{\frac{A}{\pi}} = \sqrt{\frac{300}{\pi}} \approx 9.772 \text{ cm} \]
Step 2: Calculate the Circumference from the Radius
Using the radius \( r \approx 9.772 \) cm, we can find the circumference \( C \) using the formula:
\[ C = 2 \pi r \]
Substituting the value of \( r \):
\[ C = 2 \pi \times 9.772 \approx 61.40 \text{ cm} \]
Final Answer
The circumference of the circle is:
\[ \boxed{61.40 \text{ cm}} \]
The answer is A.