basic terms related to circle

• A set of all points equidistant from a given point called center.

  Circle
• The total distance AROUND the circle.

  Circumference
• The distance from the center to the perimeter

  Radius
• plural form of radius

  radii
• The distance ACROSS the circle and twice the radius

  diameter
• Part of the circumference 


  Arc
• Line segment that passes from one point to another. (doesnt pass through the center


  chord
• A line that intersects a circle at exactly one point.

  Tangent line
• A line that intersects a circle at two points

  Secant line
• An angle made from points sitting on the circle's edge or simply, formed by two chords.


  inscribed angle
• Angle with the vertex at the center or the circle or simply an angle formed by two radius (radii) that originate from the center 


  central angle