1. Going Around in Circles!
Chapter 10 – Honors Geometry

2. Parts of a Circle and their Definitions
Set of all points in a plane that are a given distance from a given point in the plane.
Center The given point referred to in the definition of the circle. A circle is named by its center!
CENTER
Given point
Given distance
RADIUS
Radius The given distance referred to in the circle definition – the segment connecting the center to the circle – the distance from the center to the circle.

3. Parts of a Circle and their Definitions
Concentric Circles
Two or more coplanar circles with the same center

4. Parts of a Circle and their Definitions
A point is inside (in the interior) a circle if its distance from the center is less than the radius.
A point is on a circle if the distance from the center is equal to the radius.
A point is outside (in the exterior) a circle if its distance from the center is more than the radius.
POINT on a circle
INTERIOR of a circle
EXTERIOR of a circle

5. Parts of a Circle and their Definitions
Chord
A chord of a circle is a segment that connects any two points on the circle.
A chord that passes through the center is called the DIAMETER of the circle

6. Parts of a Circle and their Definitions
Circumference
The perimeter of or distance around a circle is called the circumference of a circle.
Check out about how the circumference of the earth was found

7. Parts of a Circle and their Definitions
Area of a Circle

8. Parts of a Circle and their Definitions
Enjoy the video!
Circles Radius Diameter & Pi from Math Upgrade

9. Theorems for Circle Radii and Chords
If a radius is perpendicular to a chord then it bisects the chord
If a radius of a circle bisects a chord that is not a diameter, then it is perpendicular to that chord.
The perpendicular bisector of a chord passes through the center of the circle.

10. Let’s try some problems!
Circles!
Let’s try some problems!

11. Theorems for Circle Congruent Chords
If two chords of a circle are equidistant from the center, then they are congruent.
If two chords of a circle are congruent, then they are equidistant from the center of the circle.