9.1: Circle Geometry Terminology

Vocabulary

Radius - a line from the centre of the circle to the edge

Diameter - a line from one side of the circle to the other side through the centre

Circumference - the distance around the outside of a circle

Tangent - a line from outside the circle that just touches the edge of the circle in one place only

Arc - part of the circumference of a circle

• major arc - greater than a semicircle

• minor arc - less that a semicircle

Chord -  a line segment joining two points of a circle

Segment - an area of the circle enclosed by a chord

Secant - a line from outside the circle that goes through two points on a circle, creating a chord 

Conjecture - a hypothesis achieved based on the information given

On your handout, label each of the parts according to the definitions. Be sure to do it in pencil so you can erase it if you make a mistake.