1. 9-8 Parts of Circles Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

2. Learn to identify the parts of a circle. Course 1 9-8 Parts of Circles TEKS 6.6.C: Geometry and spatial reasoning: describe the relationship between radius, diameter, and circumference of a circle.

3. Vocabulary circle center chord radius (radii) diameter Insert Lesson Title Here Course 1 9-8 Parts of Circles

4. A circle is the set of all points in a plane that are the same distance from a given point, called the center. Center Course 1 9-8 Parts of Circles

5. A line segment with one endpoint at the center of the circle and the other endpoint on the circle is a radius (plural: radii). Center Radius Course 1 9-8 Parts of Circles

6. A diameter is a line segment that passes through the center of the circle and has both endpoints on the circle. The length of the diameter is twice the length of the radius. Center Radius Diameter Course 1 9-8 Parts of Circles

7. A chord is a line segment has both endpoints on the circle. Center Radius Diameter Course 1 9-8 Parts of Circles Chord

8. Additional Example 1: Naming Parts of a Circle Name the circle, a diameter, and three radii. N The circle is circle Z.LM is a diameter.ZL, ZM, and ZN are radii. M Z L Course 1 9-8 Parts of Circles LN is a chord.

9. Check It Out: Example 1 Name the circle, a diameter, a chord, and three radii. The circle is circle D. IG is a diameter and also a chord.DI, DG, and DH are radii. G H D I Course 1 9-8 Parts of Circles