Enter any one measurement — radius, diameter, circumference, or area — and get the other three.
① ANSWER
④ Visualization
② Steps
③ Why this works
Every circle measurement is locked to the radius by fixed ratios: the diameter is always twice the radius, the circumference is the diameter times π (the constant ratio of every circle’s perimeter to its diameter), and the area grows with the square of the radius (πr²) because area is two-dimensional. Knowing any one measurement fixes the radius — and the radius fixes everything.
