Difference between revisions of "Introduction to chords"
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=== Objectives === | === Objectives === | ||
− | + | Understand chords as elements of a circle | |
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===Estimated Time=== | ===Estimated Time=== | ||
+ | 30 minutes | ||
=== Prerequisites/Instructions, prior preparations, if any === | === Prerequisites/Instructions, prior preparations, if any === | ||
+ | Prior knowledge of point, lines, angles, polygons | ||
===Materials/ Resources needed=== | ===Materials/ Resources needed=== | ||
+ | * Digital : Computer, geogebra application, projector. | ||
+ | * Non digital : Worksheet and pencil, compass, strings | ||
+ | * Geogebra files : Introduction to chords.ggb | ||
+ | |||
===Process (How to do the activity)=== | ===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) | |
− | What | + | 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 points 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 | ||
+ | {| class="wikitable" | ||
+ | |Circle | ||
+ | |Radius | ||
+ | |Chord | ||
+ | |Chord Length | ||
+ | |- | ||
+ | |1 | ||
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+ | |2 | ||
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+ | |3 | ||
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+ | |1 | ||
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+ | |} |
Revision as of 16:03, 7 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
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 points 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 |