1. 8-1A Inscribed and Circumscribed Figures What is a circle? What are the parts of a circle? What does inscribed mean? What does circumscribed mean?

2. Definition A circle is the locus of points in a plane equidistant from a given point. That point is the center of the circle. center

3. Circle Parts A circle is named by its center. A radius is a segment from the center to any point on the circle. A diameter is a segment that contains the center of the circle and has endpoints on the circle. סּQסּQ סּQ radius diameter

4. Exterior, Interior, Concentric interior exterior Concentric circles are two coplanar circles with the same center.

5. Try It N M T S X Z Name a radius of סּT. Name a diameter of סּT Describe the locations of points X and Z. If the diameter of סּT is 4 cm, what is the radius?

6. Inscribed or Circumscribed? When you draw a polygon that fits perfectly inside a circle, it is inscribed in the circle. At the same time, the circle is circumscribed around the polygon. The pentagon is inscribed in the circle. All of its vertices are on the circle. The triangle is circumscribed around the circle. Each side touches the circle at exactly one point.

7. What is a circle? A circle is the locus of points in a plane equidistant from a given point. What are the parts of a circle? Center, radius, and diameter. What does inscribed mean? A polygon that fits perfectly inside a circle. What does circumscribed mean? The figure goes around the outside.

8. Assignment 8-1A Page 542, 1-5, 8-12, 22-24