Basic constructions

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Season 3 • Episode 05 • Basic constructions

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Basic constructions

Season 3

Episode 05 Time frame 1 period

Objectives :

•

^Disover ^the ^rules ôf ^ruler ând ômpass^geometry.

•

^Study ^a ^few ^basi onstrutions.

Materials :

•

^Ruler ^and ^ompass.

•

^T^ask ^sheet.

1 – The rules of the game 10 mins

The teaher explains the rulesof ruler and ompassgeometry. The fat that the straigh-

tedge is not marked is emphasized, as is the dierene between the ompass and the

divider.

2 – Challenge : basic constructions 45 mins

Students work in groups of 4 or 5. They have to use the ruler and ompass to do some

simple onstrutions. Every onstrution must be validated by the teaher before the

groupproeedstothe next onstrution.Atthe endofthe houreverystudentshandsout

a personnal paper that willbe gradedby the teaher.

1

^. ^Copy â ^given ^lengthônâ ^line.

2

^. ^Biset ^a^line ^segment.

3

^. ^Construt ^a perpendiular toa lineat apointon the line.

4

^. ^Construt ^a perpendiular toa linefrom apointnot on the line.

5

^. ^Construt ^an ^angle^bisetor.

6

^. ^Copy ^an^angle.

7

^. ^Construt â ^parallel^to â ^line ^through â ^given ^point ^(without ^drawing âny ^perpen-

diular tothe line).

8

^. ^Partition â ^segment întoⁿ ôngruent ^segments.

9

^. ^Divide â ^segment întoâ ^given ^ratio ^(forêxample ³ ^to^2).

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