Difference between revisions of "Introduction to chords"
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| Line 11: | Line 11: | ||
* 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 : Introduction to chords.ggb | + | * Geogebra files : [https://ggbm.at/hkqkamre Introduction to chords.ggb] |
| + | {{Geogebra|hkqkamre}} | ||
===Process (How to do the activity)=== | ===Process (How to do the activity)=== | ||
| Line 21: | Line 22: | ||
* Mark any two points on the circumference of a circle, join the two points. What is this line? | * Mark any two points on the circumference of a circle, join the two points. What is this line? | ||
* Establish chord. | * Establish chord. | ||
| − | * Move the | + | * Move the slider to show how the chord length varies. Ask students to observe the changing chord lengths and when the chord length is maximum. Compare chord length with diameter. |
* How many parts is the circle divided into by the chord? What do you notice about these two parts? | * How many parts is the circle divided into by the chord? What do you notice about these two parts? | ||
Revision as of 10:30, 17 May 2019
Objectives
Understand chords as elements of a circle
Estimated Time
30 minutes
Prerequisites/Instructions, prior preparations, if any
Prior knowledge of point, lines, angles, polygons
Materials/ Resources needed
- Digital : Computer, geogebra application, projector.
- Non digital : Worksheet and pencil, compass, strings
- Geogebra files : Introduction to chords.ggb
Download this geogebra file from this link.
Process (How to do the activity)
Hands-on work:
- Students to make a circle with thread/ string. Stick on a paper. The centre should be marked.
- Mark points on the circumference of the circle and measure the chord length.
- Measure the longest chord length. What is special about the longest chord? (Students should be able to say it passes through the centre)
Use geogebra file: Introduction to chords
- Mark any two points on the circumference of a circle, join the two points. What is this line?
- Establish chord.
- Move the slider to show how the chord length varies. Ask students to observe the changing chord lengths and when the chord length is maximum. Compare chord length with diameter.
- How many parts is the circle divided into by the chord? What do you notice about these two parts?
- Establish Segments. When will the two segments in a circle be equal?
- Note chord length for circles with different radius
| Circle | Radius | Chord | Chord Length |
| 1 | 1 | ||
| 2 | |||
| 3 | |||
| 4 | |||
| 2 | 1 | ||
| 2 | |||
| 3 | |||
| 4 |