View source for Congruent chords are equidistant from the centre of a circle

In the same circle or in circles of equal radius:

• Equal chords are equidistant from the centre.

• Conversely, chords that are equidistant from the centre are equal. 

===Objectives===
Understanding equal chords are at equal distance from the centre

===Estimated Time===
40 minutes

===Prerequisites/Instructions, prior preparations, if any===
Basics of circles and its related terms should have been done.

===Materials/ Resources needed===
* Digital : Computer, geogebra	application, projector.
* Non	digital : Worksheet	and pencil, compass, strings
* Geogebra	files :  Equal	chords and distance from center.ggb, Equidistantchords.ggb
This geogebra file has been created by Tharanath Achar of Dakshina kannada.

{{Geogebra|hyvd3h4y}}{{Geogebra|yd4qtqqb}}

===Process (How to do the activity)===
__FORCETOC__

Developmental Questions  
# What is a chord ?
# Name the centre of the circle.
# How do you draw congruent chords in a circle ?
# How many chords do you see in the figure ? Name them.
# If  both the chords are congruent, what can you say about the length of both the chords ?
# How can we measure the length of the chord ?
# What is the procedure to draw perpendicular bisector ?
# What does theorem 1 say ? Do you all remember ?
# What is the length of both chords here ?
# What can you conclude ?
# Repeat this for circles of different radii and for different lengths of congruent chords.
Equal chords and distance from center.ggb
# Two	chords equal chords are at equal angles with diameter from	a point on the circle.
# Identify the congruent elements for the triangles formed when	perpendicular is drawn to chords from center of the circle.
# Can these equal chords be any where in the circle, then what about	their perpendicular distances.
Equidistantchords.ggb
# Use the files to demonstrate equal chords are at equal distance from	the center
# Show the animation by overlapping the two chords to show they are	equal
* '''Evaluation Questions'''
# Were the students able to comprehend the drawing of congruent chords in a circle ?
# Were the students able to comprehend why congruent chords are always equal for a given circle. Let any student explain the analogy.
# Are the students able to understand that this theorem can be very useful in solving problems related to circles and triangles ?
# What is a chord ?
# What are congruent chords ?
# Why do you think congruent chords are always equal for a circle of given radius ?

[[Category:Circles]]