How to find the ratio of diameter and circumference - PSAT Math

Card 0 of 7

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

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The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$

Let represent the area of a circle and represent its circumference. Which of the following equations expresses in terms of ?

Tap to see back →

The formula for the area of a circle is $A=\pi $r^2$$ , and the formula for circumference is $C=2\pi r$ . If we solve for C in terms of r, we get
$r=C/2\pi$ .

We can then substitute this value of r into the formula for the area:

$A=\pi $r^2$$

$=\pi (C/2\pi $)^2$$