1. Extension #4A Geometry Math Vocabulary- Circles Assessment Anchor M5.B PA Academic Standard 2.9.5C Aligning with Pennsylvania Department of Education Assessment Anchor/ Academic Standard ©2011 Caryn Dingman www.mrsdingman.com

2. 2 circle Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C * a closed plane figure * all points on figure are same distance from center point * has no beginning point and no ending point * named by a point in the center

3. 3 circumference Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C * distance around outer edge of circle

4. 4 chord Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C * a line segment * connects ANY 2 points on a circle

5. 5 radius Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C * a line segment * connects center point of circle with point on outer edge of circle

6. 6 diameter * is a line segment * connects center point of circle with points on outer edge of circle * is a chord Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C

7. 7 formula to find diameter * to find diameter when radius is given, multiply radius by 2 Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C radius = 4cm diameter = 2r d = 2 X 4cm d = 8cm

8. 8 formula to find radius * to find radius when diameter is given, divide diameter by 2 Extension #4A Geometry- Circles PA Assessment Anchor M5.B/ Academic Standard 2.9.5C diameter = 3 in. radius = d ÷ 2 r = 3 in. ÷ 2 r = 1.5 in.