Answer:
To find a circle given its diameter, you can use the following formula:
C = πd
where C is the circumference of the circle, d is the diameter, and π (pi) is a mathematical constant approximately equal to 3.14.
If you want to find the area of the circle, you can use the following formula:
A = πr²
where A is the area of the circle, and r is the radius (which is half the diameter).