circle geometry

Table of Contents

• angle proportional to arc

  • Angle at Center
  • Angle at Center with spreadsheets
  • Arc and Angle
  • eyeball model
  • Spotlight
  • compare angles and arcs

• angles at circumference

  • Angle at circumference
  • angle at center and circumference
  • Equal angles in circle; various theorems

• concyclic points

  • mark equal angles
  • vary and mark an angle
  • drag and trace an angle
  • drag and trace an angle with color
  • make 4 points concyclic

• tangents

  • exploring tangent-chord angle
  • studying tangent-chord angles
  • tangent chord angles

• proof and explanation

  • explain difference in angles with circle
  • angle at center and circumference proof

• equidistance

  • equidistant from 2 points
  • equidistant from 3 points
  • task: circumcenter

• exercise

  • Annulus
  • circles
  • maximize an angle
  • maximum angle explained
  • task: angle and chord
  • task: rectangle length
  • task: chord midpoint
  • task: make center
  • task: make right angle
  • task: make an angle

• links

  • seeing tangent and chord from an alternate angle
  • Circle Geometry resources in gMath