Find the diameter and the radius of a circle with a circumference of 465 cm. Give the answer to the nearest centimetre. Use π = 3۰142 or the π button on a calculator.

After you make it all the way around, the program calculates the circumference and radius of your circle—and from that, the value of pi. You can see the code by clicking the pencil icon.

Remember that the third side — which is equal to 3√2 — is the circle's diameter. We're trying to find circumference, which, as stated earlier, is equal to pi times diameter (c = πd).

Every year, the celebration of Pi Day (March 14 is 3.14) grows more ambitious. Math teachers love to dream up unique classroom activities to celebrate Pi for it endless opportunity to calculate (3 ...

Around 250 B.C., the Greek mathematician Archimedes calculated the ratio of a circle's circumference to its diameter. A precise determination of pi, as we know this ratio today, had long been of ...

Let’s say we have a circle with a radius of exactly that size (or 25 billion miles in diameter) and we want to calculate the circumference, which is pi times the radius times 2.