there’s 2 basic cases you’ll see to find the diameter (a line that basically cuts the circle in half)
you’ll either be given the radius (the distance between the center of the circle to any point on the circle) or the circumference (the perimeter of the circle)
so you have two equations:
diameter= 2*radius
circumference= diameter * pi
if they gave you the radius, simply multiply by 2 as the first equation states. if they give you the circumference, divide the circumference by pi (which is approx. 3.14)
If you know the radius of the circle, double it to get the diameter. The radius is the distance from the center of the circle to its edge. If the radius of the circle is 4 cm, then the diameter of the circle is 4 cm x 2, or 8 cm. If you know the circumference of the circle, divide it by π to get the diameter
