👉 In geometry, a radius of a circle is a line segment from the center of the circle to any point on the circumference. This line segment has a length equal to the radius when it passes through the center and makes an angle of 90 degrees with the horizontal plane. For example, if you have a circle with a radius of 5 units, then its center is at (0, 0) and the radius is 5 units. The point on the circumference that is directly above