1. Warm – up Session 16 You also need to do the Graduation Exam Packet Page 2.

2. AGENDA 1.Tests are not graded 2.Notes 10.1 - Circles 3.Class Work 4.Home Work Wed 3/1 10.2 Fri 3/3 10.3 Tue 3/7 QUIZ 10.1-10.3 Notes 10.4

4. 10.1 Parts of a Circle Circle – set of all points _________ from a given point called the _____ of the circle. C Symbol: equidistant center C

5. CHORD: a segment whose ________ are on the circle endpoints

6. P RADIUS: distance from the _____ to a point on the circle center Radius

7. Diameter P DIAMETER: distance ______ the circle through its ______ center across Also known as the longest chord.

8. What is the relationship between the diameter and the radius of a circle? r = OR D = ½ D 2 r

9. D = ? r = ? D = ?

10. Use  P to determine whether each statement is true or false. P Q R T S

11. Secant Line A secant line intersects the circle at exactly TWO points.

12. TANGENT: a LINE that intersects the circle exactly ONE time

13. Point of Tangency

14. Name the term that best describes the notation. Secant Radius Diameter Chord Tangent

15. Two circles can intersect… in two points one point or no points

16. No points of intersection (different center)

17. No points of intersection (same center) Same center but different radii

18. 1 point of intersection (Tangent Circles) Internally Tangent Externally Tangent

19. 2 points of intersection

20. Common Tangents Internal

21. Common Tangents External

22. INTERIOR A point is inside a circle if its distance from the center is less than the radius. 

23. EXTERIOR A point is outside a circle if its distance from the center is greater than the radius. 

24. A point is on a circle if its distance from the center is equal to the radius. 

25. If a line (segment or ray) is tangent to a circle, then it is perpendicular to the radius drawn to the point of tangency. Point of Tangency More Pythagorean Theorem type problems! Yeah!!

26. a 2 + b 2 = c 2 x = 15 9 2 + 12 2 = x 2

27. a 2 + b 2 = c 2 RQ = 16 12 2 + (QR) 2 = (8+12) 2 12 2 + (QR) 2 = 20 2

28. r 2 + 24 2 = (r + 16) 2 r = 10 r 2 + 576 = r 2 + 32r + 256 320 = 32r

29. R S T If two segments from the same exterior point are tangent to a circle, then they are congruent. Party hat problems!

30. R S T

31. A C B

32. A C E B D P

33. T S Q P N R