Parts of a Circle

3. Parts of a Circle _____– set of all points _________ from a given point called the _____ of the circle (in a plane). C Symbol:

4. CHORD: a segment whose ________ are on the circle

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

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

7. D = ? 32 12 r = ? r = ? 6 D = ? 9

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

9. A _______________ intersects the circle at exactly TWO points.

10. A _________ is a LINE that intersects the circle exactly ONE time

11. Point of _______

12. Name the term that best describes the line. ______?___ ______?____ ________?__ _______?___ _______?___

13. No points of intersection (same center) _______ Circles Same center but different radii

14. Central Angle : An Angle whose vertex is at the center of the circle ACB AB A Major Arc Minor Arc More than 180° Less than 180° P To name: use 3 letters C To name: use 2 letters B <APB is a Central Angle

15. EDF Semicircle: An Arc that equals 180° To name: use 3 letters E D P F

16. measure of an arc = measure of central angle m AB m ACB m AE A E 96 Q = B C = =

17. Arc Addition Postulate m ABC = m + m A C B

18. m DAB = Tell me the measure of the following arcs. D A 140 m BCA = R 40 100 80 C B

19. CONGRUENT ARCS Congruent Arcs have the same measure and MUST come from the same circle or of congruent circles. C B D 450 450 110 A