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 radius of a circle or a sphere is the distance between the center and the edge. The radius can be used to calculate a circle's diameter, area and circumference.

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?

The radius of the circle is 8 cm. Substitute 𝒓 = 8 into the formula for the area of the circle. Multiply π by the square of the radius. 3۰14 × 82 = 200۰96.