Difference between revisions of "Secant and tangent of a circle"

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A tangent is a line touching a circle in one point.  A secant is the line through two distinct points on a circle.
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===Objectives===
 
===Objectives===
#The secant is a line passing through a circle touching it at any two points on the circumference.
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To understand tangent and secant of a circle.
#A tangent is a line touching the circle at only one point on the circumference.
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===Estimated Time===
 
===Estimated Time===
 
30 minutes
 
30 minutes
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* Digital : Computer, geogebra application, projector.
 
* Digital : Computer, geogebra application, projector.
 
* Non digital : Worksheet and pencil, compass, strings
 
* Non digital : Worksheet and pencil, compass, strings
* Geogebra files :  Lines in a circle.ggb 
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* Geogebra files :  [https://ggbm.at/mfeqt8w4 Lines in a circle.ggb] 
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{{Geogebra|mfeqt8w4}}
  
 
===Process (How to do the activity)===
 
===Process (How to do the activity)===

Revision as of 10:59, 17 May 2019

A tangent is a line touching a circle in one point. A secant is the line through two distinct points on a circle.

Objectives

To understand tangent and secant of a circle.

Estimated Time

30 minutes

Prerequisites/Instructions, prior preparations, if any

  • The students should have a prior knowledge about a circle and its basic parts and terms.
  • They should know the clear distinction between radius, diameter, chord, secant and tangent.

Materials/ Resources needed

  • Digital : Computer, geogebra application, projector.
  • Non digital : Worksheet and pencil, compass, strings
  • Geogebra files : Lines in a circle.ggb 


Download this geogebra file from this link.


Process (How to do the activity)

  • The teacher can show the geogebra file.
  • Move the points on circumference and explain secant.
  • When both endpoints of secant meet, it becomes a tangent.
  • Name the points on the circumference of the circle.
  • At how many points is the line touching the circle ?
  • What is the line called ?
  • Evaluation Questions
  1. What is the difference between the secant and a tangent?
  2. What is the difference between the chord and a secant ?
  3. Can you draw a secant touching 3 points on the circle ?
  4. At how many points does a tangent touch a circle ?
  5. How many tangents can be drawn to a circle ?
  6. How many tangents can be drawn to a circle at any one given point ?
  7. How many parallel tangents can a circle have at the most ?