How do you find the area of a circle? Can you measure the area of a circle and use that to find a value for Pi?

Why is the area of a circle proportional to the square of its radius? And why is that ratio the same as the ratio of the circumference to the diameter?

Learn how to calculate the areas of rectangle, triangle, and circle in Excel for a single cell or range of cells usin this formula.

The area of a circle is pi times the radius squared. This is half of a circle with a radius of 1 (no units) such that it would have an area of pi/2.

One of the oldest calculus problems, finding the area of a circle, can be visualized using a pizza. By dividing it up into ever smaller slices and laying them out next to one another, eventually ...