Find the area of the circle if the circumference is 12. Round to the nearest tenth.

Question 20 options:

10.46 sq units

11.46 sq units

11.86 sq units

12 sq units

1 answer

To find the area of the circle when the circumference is given, we can use the formulas for circumference and area of a circle.

  1. The formula for circumference \( C \) is: \[ C = 2\pi r \] where \( r \) is the radius.

  2. The formula for area \( A \) is: \[ A = \pi r^2 \]

Given that the circumference is 12, we can find the radius:

\[ 12 = 2\pi r \]

To solve for \( r \): \[ r = \frac{12}{2\pi} = \frac{6}{\pi} \]

Now we can find the area using the radius: \[ A = \pi r^2 = \pi \left(\frac{6}{\pi}\right)^2 = \pi \cdot \frac{36}{\pi^2} = \frac{36}{\pi} \]

Now we will calculate the area:

Using \(\pi \approx 3.14\): \[ A \approx \frac{36}{3.14} \approx 11.46 \]

Rounding to the nearest tenth, the area is approximately \( 11.5 \) square units.

However, looking at the given options, the closest match to our calculated area is:

11.46 sq units.