A circle has a circumference of c.

What is the area of the circle, a,
in terms of c?

Responses

a=c24π
a=c24π

a=2c
A is equal to 2 c

a=πc2
a=πc2

a=cπ

1 answer

To find the area of a circle in terms of its circumference, we start with the formulas for circumference and area.

  1. The circumference \( c \) of a circle is given by: \[ c = 2\pi r \] where \( r \) is the radius.

  2. From this, we can solve for the radius \( r \): \[ r = \frac{c}{2\pi} \]

  3. The area \( a \) of a circle is given by: \[ a = \pi r^2 \]

  4. Substituting the expression for \( r \) into the area formula: \[ a = \pi \left(\frac{c}{2\pi}\right)^2 \]

  5. Simplifying this expression: \[ a = \pi \cdot \frac{c^2}{(2\pi)^2} \] \[ a = \pi \cdot \frac{c^2}{4\pi^2} \] \[ a = \frac{c^2}{4\pi} \]

So, the area \( a \) of the circle in terms of its circumference \( c \) is: \[ a = \frac{c^2}{4\pi} \]

The correct response is: a = \(\frac{c^2}{4\pi}\).