1. Equation of a Circle

2. Warm Up 1. 2.

3. Circle
A Circle is a set of all points in a plane equidistant from a given point called the center.

4. Circle
Equation Centered at the Origin: Centered at (h,k): (x,y) is any point on the circle (h,k) is the center point r is the radius

5. Identifying the Center and Radius
Find the Center and the Radius

6. Identifying the Center and Radius
Find the Center and the Radius

7. Writing an equation of a Circle
Given the center and the radius, write an equation of a circle. Center (-4,3) and radius 4

8. Try Some!
Given the center and the radius, write an equation of a circle.

9. Try Some!
Given the center and the radius, write an equation of a circle.

10. Writing an Equation From a Graph

11. Graphing Circles
Graph the following circle.

12. Completing the Square
Use Completing the Square find the center and the radius!

13. Completing the Square
Use Completing the Square find the center and the radius!

14. Completing the Square
Use Completing the Square find the center and the radius then find Circumference and Area. x2 + 2x + y2 + 14y – 31 = 0

15. Completing the Square
Use Completing the Square find the center and the radius then find Circumference and Area. x2 - 10x + y2 + 4y – 7 = 0