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A circle is a geometric shape that consists of all the points in a plane that are equidistant from a fixed point called the center. The distance from the center to any point on the circle is called the radius, and twice the radius is called the diameter. The circumference of a circle is the distance around its outer edge.
There are several types of circles based on different characteristics:
1. Unit Circle: A unit circle is a circle with a radius of 1 unit. It is often used in trigonometry to define the values of trigonometric functions.
2. Concentric Circles: Concentric circles are circles that share the same center but have different radii. They form a series of circles with increasing or decreasing radii.
3. Tangent Circles: Tangent circles are circles that intersect at exactly one point, and the point of intersection is known as the point of tangency. The tangent line to a circle at the point of tangency is perpendicular to the radius of the circle at that point.
4. Inscribed Circle: An inscribed circle is a circle that is contained within a polygon, touching each side of the polygon at exactly one point. The center of the inscribed circle is the incenter of the polygon.
5. Circumcircle: A circumcircle is a circle that passes through all the vertices of a polygon. The center of the circumcircle is the circumcenter of the polygon.
6. Ellipse: An ellipse is a type of circle that is elongated in one direction. It is defined by two foci and has the property that the sum of the distances from any point on the ellipse to the two foci is constant.
7. Semicircle: A semicircle is exactly half of a circle, and it is formed by cutting a circle along its diameter.
These are some of the types of circles with their distinguished characteristics. Circles have various properties and applications in mathematics, physics, engineering, and many other fields.