When you draw straight lines inside or touching a circle, you can form several types of angles. The three main ones are: the central angle, the inscribed angle, and the semi-inscribed angle.
A central angle has its vertex at the center of the circle. Its two sides are radii, and the endpoints of both sides lie on the circle.
An inscribed angle is formed when both the vertex and the two endpoints of its sides all lie on the circle.
An inscribed angle equals half the arc it spans.
A semi-inscribed angle has its vertex on the circle. It is formed by a chord (a line connecting two points on the circle) and a tangent at the vertex (a line that touches the circle at exactly one point).
Click on any element to learn more.
