Introduction to Circles

What is this an example of?

• radius

• Diameter

• chord

• secant

What is this an example of?

• radius

• diameter

• secant

• tangent

If a radius is 5 cm then what is the length of the diameter?

If a diameter is 36 cm then what is the radius?

Which segment is the diameter?

• DE

• BO

• AO

• AB

Which segment is a radius?

• RO

• AO

• OB

• all the above

Which point is the center?

• O

• A

• B

• C

Pythagorean review: If a is 8 and c is 9 then what is b?

• 2

• $\sqrt{145}$

• $\sqrt{17}$

Use previous knowledge to figure out how to solve for line segment RP. (use Pythagorean theorem)

• 74.45

• $\approx\ 8.65$

• $\approx5.67$

What is the definition of the center of a circle?

• A segment whose endpoints are on a circle.

• An angle whose vertex is the center of a circle.

• The point from which all points on a circle are equidistant.

• Two endpoints on a circle and all of the points on the circle between those two endpoints.