Visual Glossary
By: Jack Eike
Sector: A portion of the circle that is made up of two radii and an arc. A baseball field is an example of a sector of a circle.
Chord: A segment whose endpoints are on the circle. A segment is formed with a chord.
Segment: A region that is formed by a chord and an arc. A segment resembles a semicircle but is not because it does not use the diameter.
Semicircle: A region that is formed by the diameter of the circle and the arc. A semicircle is exactly half of a full circle and it's arc is 180 degrees.
Tangent: A line that intersects the circle at one point. A tangent line is always perpendicular to the radius that is at the point of tangency.
Inscribed Angle: An angle that is made up of two chords of a circle. An inscribed angle is half the intercepted arc and half the central angle with the same endpoints.
Intercepted Arc: An arc that is broken off the circle by two points on the circle. They are formed by an interior or exterior angle.
Tangent Segment: A segment of a tangent line. A tangent segment is on the outside of the circle.
Arc Length: The length of the broken arc from the circle. Arc length is measured in radians.
I choose these 9 things because I felt that these are the important and some of the most used things in this unit. Arc length for example we used in 2 different lessons and it was embellished in the other lessons that were ahead of it. Another few we used a lot were intercepted arc and inscribed angle. Those were probably the most used things in this unit.