Topicm0e15fb9fdf488e9b_1528449000663_0Topic

Parallel linesparallel linesParallel lines and line segments

Levelm0e15fb9fdf488e9b_1528449084556_0Level

Second

Core curriculumm0e15fb9fdf488e9b_1528449076687_0Core curriculum

VII. Lines and line segments

The student:

2) Identifies lines and line segments, perpendicular and parallel, like the example below:

The line segments AB and CD are perpendicular, the line segments CD and EF are parallel. Determine the mutual position of line the segments DF and AB.

Make a proper drawing

3) draws pairs of parallel and perpendicular line segmentsperpendicular line segmentsperpendicular line segments.

Timingm0e15fb9fdf488e9b_1528449068082_0Timing

45 minutes

General objectivem0e15fb9fdf488e9b_1528449523725_0General objective

Using mathematical objects, interpreting mathematical concepts.

Specific objectivesm0e15fb9fdf488e9b_1528449552113_0Specific objectives

1. Determining mutual position of lines on a plane.

2. Identifying and drawing parallel lines.

3. Identifying and drawing parallel line segments.

Learning outcomesm0e15fb9fdf488e9b_1528450430307_0Learning outcomes

The Student:

- identifies parallel lines and line segments,

- draws parallel lines and line segments.

Methodsm0e15fb9fdf488e9b_1528449534267_0Methods

1. Situational analysis.

2. Discussion.

Forms of workm0e15fb9fdf488e9b_1528449514617_0Forms of work

1. Individual work.

2. Group work.

Lesson stages

Introductionm0e15fb9fdf488e9b_1528450127855_0Introduction

Students revise what the mutual position of two lines on a plane can be.

Two lines:
- do not have any common points,
- have infinitely many common points – they are coincidental,
- have one common point – they intersect,
- perpendicular lines are a special case of intersecting lines. Whether or not they are perpendicular can be checked with a setsquare.m0e15fb9fdf488e9b_1527752263647_0Two lines:
- do not have any common points,
- have infinitely many common points – they are coincidental,
- have one common point – they intersect,
- perpendicular lines are a special case of intersecting lines. Whether or not they are perpendicular can be checked with a setsquare.

[Illustration 1]

Procedurem0e15fb9fdf488e9b_1528446435040_0Procedure

Students draw lines along both sides of the rulerrulerruler. The teacher informs them that lines drawn in such a way are calledparallel linesparallel linesparallel lines. Lines which are coincidental are also parallel.

Conclusions:

- parallel lines are lines that have zero common points or are coincidental,
- whether or not lines are parallel can be checked with a setsquare and a ruler or with two setsquares,
- the fact that line m is parallel to line n can be written down as: m ‖ n.m0e15fb9fdf488e9b_1527752256679_0- parallel lines are lines that have zero common points or are coincidental,
- whether or not lines are parallel can be checked with a setsquare and a ruler or with two setsquares,
- the fact that line m is parallel to line n can be written down as: m ‖ n.

[Illustration 2]

Task 1

Students work individually, using computers. Their task is to draw a line parallel to the given line, using two setsquares presented on the screen.

[Geogebra applet]

Task 2

Students draw parallel linesparallel linesparallel lineswhich:

a) have zero common points,
b) are coincidental.

Task 3

Students draw two parallel lines. They mark three points on each of them. They point out the created parallel line segmentsparallel line segmentsparallel line segments.

Conclusion:

The line segments AB and CD are parallel, if they are located on parallel linesparallel linesparallel lines. We write it down as: AB ‖ CD.

Task 4

Students draw the ABCD rectangle. Their task is to write down all created:

a) parallel line segmentsparallel line segmentsparallel line segments,
b)perpendicular line segmentsperpendicular line segmentsperpendicular line segments.

An extra task:

Draw three parallel linesparallel linesparallel lines a, b and c and two lines m and n that are perpendicular to them. Write down all pairs of parallel lines and all pairs of perpendicular linesperpendicular linesperpendicular lines in the pictures.

Lesson summarym0e15fb9fdf488e9b_1528450119332_0Lesson summary

Students do the revision exercises. Then together they sum‑up the classes, by formulating the conclusions to memorise.

- parallel lines are lines which have zero common points or are coincidental,
- whether or not lines are parallel can be checked with a setsquaresetsquaresetsquare and a rulerrulerruler or with two setsquares,
- the fact that line m is parallel to line n can be written down as: m ‖ n.

Selected words and expressions used in the lesson plan

parallel linesparallel linesparallel lines

parallel line segmentsparallel line segmentsparallel line segments

perpendicular linesperpendicular linesperpendicular lines

perpendicular line segmentsperpendicular line segmentsperpendicular line segments

setsquaresetsquaresetsquare

rulerrulerruler

intersecting linesintersecting linesintersecting lines

coicindental linescoicindental linescoicindental lines

common pointcommon pointcommon point