2 Write down as many things as you know about this shape. Circle GeometryWrite down as many things as you know about this shape.
3 Circle Geometry1. Radius (r) – The distance from the center of a circle to the outside edge. Plural is radii. 2. Diameter (d) – The distance from one side of a circle to the other, passing through the center. 3. Pi (π) – The ratio of the circumference of a circle to its diameter (C/d). 4. Circumference (C = 2πr or C = πd ) – The distance around a circle. 5. Area (A = πr2) – The space covered by a 2-D circle.
4 Circle Geometry6. Semi-Circle – Exactly half of a circle. 7. Chord – A line segment joining two points on a curve. 8. Minor Arc – A portion of a circle less than a semi-circle. 9. Major Arc – A portion of a circle equal to, or more than, a semi-circle.
5 Circle Geometry10. Central Angle – An angle formed by two radii of a circle.11. Inscribed Angle – An angle formed by two chords whichintersect on the circle.12. Tangent – A line intersecting a circle at only one point.13. Circumscribed Angle – An angle outside of a circle formed bytwo lines that are tangent to a circle.
6 Circle Geometry14. Secant – A line intersecting a circle at two points.