PARTS OF A CIRCLE

• Center - has a fixed point, and generally denoted by "O"
• Diameter - A chord passing through the center
• Diameter - This is the longest chord and is twice the radius
• Diameter - Dividdes the circle into two equal parts
• Radius - It is the distance from the center to any point on the circle
• Radius - Half the diameter
• Chord - A line segment joining any 2 points in the circumference
• Segment - Region enclosed by a chord and an arc
• Arc - Portion of the circumference
• Two types of Arc:

  • Major Arc
  • Minor Arc
• Minor Arc - Shorter than the half of the circumference
• Major arc - More than the half of the cirucumference
• Sector - A region bounded by 2 radii and an arc
• Semi Circle - region enclosed by a diameter and arc
• Tangent - A line which touches a circle at one point
• Secant - A line that touches 2 points in the circumference
• Angles in a Circle:

  • Central Angle
  • Inscribed Angle
• Central Angle - Whose vertex is the center of the circle
• Central Angle - Composed of 2 radii
• Inscribed Angle - Formed by 2 chords
• Inscribed Angle - The vertex is at the circle(not inside but the actual circle itself)
• Arc - Part or subset of a circle
• Circumference - Distance around a circle
• Minor arc - A type of arc whose degree measure is less than 180
• Major arc - A type of arc whose degree measure is more than 180
• Semi-Circle - An arc of a circle whose degree measure is exactly 180 degrees