The radius of a circle is equal to the distance from the center of the circle to any point on the circumference. Usually, the radius is denoted with “R” or with “r“. This quantity is very important in geometry and appears in almost all formulas related to circles....

The circumference of a circle defines the length of the contour of the circle. The circumference is also referred to as the perimeter of the circle since it is a measure of the limits of the circle. The circumference can be calculated using the length of the diameter...

The area of a circle is the region occupied by the circle in the two-dimensional plane. We can easily determine this area using the formula A = πr², where r is the length of the radius of the circle and where π is a mathematical constant...

The perimeter of any figure defines the path or the boundaries that enclose the figure. The perimeter of a circle is also called the circumference and it tells us the length of the path around the circle. This length can be calculated using the...

Octagons are polygons that have eight sides and eight interior angles. The total sum of the interior angles in an octagon is equal to 1080°. We can define some types of octagons depending on the characteristics that we consider. For example, based on the lengths of...