The formula for the area, a, of a circle is a = πr2 , where r is the circle’s radius, and the formula for the circumference, c, of a circle is c = πd , where d is the circle’s diameter. which statement is correct?

The formula for the circumference, C, of a circle is C = πd , where d is the circle’s diameter.

Step-by-step explanation:

For a circulus with radius r, we have that:

The area of the circulus is:

That is, the radius is squared, not multiplied by 2, so the first statement is incorrect.

The circumference of the circulus is:

The derivative of the area, so

However

The radius if half the diameter. So

So the correct statement is:

The formula for the circumference, C, of a circle is C = πd , where d is the circle’s diameter.

what is the model?

step-by-step explanation: