Circle Definitions and Theorems Vocabulary

A segment that has one endpoint at the center and the other endpoint on the circle is the __________.

• diameter

• chord

• radius

• secant

An angle whose vertex is the center of a circle is a(n) ______.

• inscribed angle
• acute angle
• obtuse angle
• central angle

A tangent line of a circle is...

• It's diameter
• It's radius
• It's circumference
• A line that touches the circle only once

A chord is a segment that connects ___________

• the center to the endpoint
• to one point outside the circle
• a central angle
• 2 endpoints of a circle

Two circles are congruent if they have the same __________

• Center 
• Radius
• Inscribed Angle
• Central Angle

Two circles are concentric if they have the same ______

• Center
• Radius
• Central Angle 
• Inscribed Angle

True or False: An equation for Circumference is C = πr²

• True 
• False

Which of the following names a diameter?

• segment AC
• segment DB
• segment AB
• segment BC

What is the part of the circle highlighted in red called?

• semi-circle arc
• major arc
• minor arc
• sector

What is the part of the circle highlighted in red called?

• semi-circle arc
• major arc
• minor arc
• sector