AI Math SolverThe diameter of a circle is the longest distance across it, passing through the center — equal to twice the radius. Learn the definition and how to find it from radius or circumference.
Solve it with the AI Math SolverThe diameter cuts the circle in half through the center. Every diameter is twice the radius, and it is the longest chord you can draw in a circle.
If you know the radius, double it. If you know the circumference, divide by π. The diameter then feeds into the area formula A = π(d/2)².
The diameter is the distance straight across a circle through its center. It equals twice the radius: d = 2r.
From the radius, use d = 2r. From the circumference, use d = C/π, since circumference equals π times diameter.