A circle has about 80 of the area of a similar-width square. As proved by Archimedes in his Measurement of a Circle the area enclosed by a circle is equal to that of a triangle whose base has the length of the circles circumference and whose height equals the circles radius which comes to p multiplied by the radius squared. Area of a Circle Segment Given the Central Angle.
Area of a circle p d2 2.
The surface area of circle is 4pr 2. P is approximately equal to 314. The formula to find the area of a circle is. The result will vary from zero when the height is zero to the full area of the circle when the height is equal to the diameter.