1. Circles Review
Unit 9

2. Standards
Standard 78: Identify and describe relationships among circles (radius, diameter, chord, tangent, secant, etc.)
Standard 79: Find the relationships between congruent and similar circles.
Standard 80: Solve problems involving tangents of circles.
Standard 81: Measure central angles and arcs of circles.
Standard 82: Describe relationships between adjacent arcs as well as between arcs and chords.
Standard 83: Find the lengths of chords in a circle.
Standard 84: Find the measure of arcs in a circle.
Standard 85: Determine the area and circumference of a circle.
Standard 86: Determine the area and circumference of a sector of a circle.

3. Standard 78: Identify and describe relationships among circles (radius, diameter, chord, tangent, secant, etc.)
Draw a circle and label each of the following:
Radius
Diameter
Chord
Tangent
Secant
Center

4. Standard 80: Solve problems involving tangents of circles.
Draw four circles and label them 1- 4.
Draw an internal tangent between circles 1 and 3.
Draw an external tangent between circles 2 and 4.

5. Standard 81: Measure central angles and arcs of circles.
Draw a circle with a central angle of 45 degrees.
Draw a circle with a radius of 12 feet and a central angle of 215 degrees.

6. Standard 82: Describe relationships between adjacent arcs as well as between arcs and chords.
What is the relationship between adjacent arcs?
What is the relationship between congruent arcs?
Draw a picture of both.

7. Standard 84: Find the measure of arcs in a circle.
Given the circle, draw an arc of 78 degrees.

8. Standard 85: Determine the area and circumference of a circle.
What is the formula for the area of a circle?
What is the formula for the circumference of a circle?

9. Standard 85: Determine the area and circumference of a circle.
There is a circle with a radius of 30 feet.
What is the area of the circle?
What is the circumference of the circle?

10. Standard 86: Determine the area and circumference of a sector of a circle.
What is the formula for the area of a sector of a circle?
What is the formula for the circumference of a sector of a circle?

11. Standard 86: Determine the area and circumference of a sector of a circle.
There is a circle with a radius of 30 feet and a sector of 38 degrees.
What is the area of the sector?
What is the circumference of the sector?