Topicma6609e8a4cfcab1b_1528449000663_0Topic

Lines and line segments

Levelma6609e8a4cfcab1b_1528449084556_0Level

Second

Core curriculumma6609e8a4cfcab1b_1528449076687_0Core curriculum

VII. Lines and line segments. The student:

1) identifies and names the figures: the pointpointpoint, the line, the ray, the line segmentline segmentline segment.

VIII. Properties of planar geometric figuresgeometric figuresgeometric figures. The student:

2) presents two lines on a planeplaneplane in different position with respect to each other, especially perpendicularperpendicularperpendicular and parallel lines.

Timingma6609e8a4cfcab1b_1528449068082_0Timing

45 minutes

General objectivema6609e8a4cfcab1b_1528449523725_0General objective

Reading, interpreting and processing data presented in different forms.

Specific objectivesma6609e8a4cfcab1b_1528449552113_0Specific objectives

1. Identifying basic geometric shapes.

2. Determining the mutual position of two straight lines.

3. Communicating in English, developing basic mathematical, computer and scientific competences, developing learning skills.

Learning outcomesma6609e8a4cfcab1b_1528450430307_0Learning outcomes

The student:

- identifies basic geometric figuresgeometric figuresgeometric figures,

- determines the mutual position of straight lines.

Methodsma6609e8a4cfcab1b_1528449534267_0Methods

1. Brainstorming.

2. Situational analysis.

Forms of workma6609e8a4cfcab1b_1528449514617_0Forms of work

1. Individual work.

2. Group work.

Lesson stages

Introductionma6609e8a4cfcab1b_1528450127855_0Introduction

The teacher introduced the topic of the lesson – revising basic geometric figuresgeometric figuresgeometric figures and the mutual position of two straight lines.

Procedurema6609e8a4cfcab1b_1528446435040_0Procedure

While brainstorming, the students revise what kind of geometric figuresgeometric figuresgeometric figures they know.

Basic geometric figuresgeometric figuresgeometric figures are:

[Illustration 1]

A line segment is the part of a straight line, located between two points, together with these points.
A point located on a straight line divides it into two parts. Each part with the point is called the ray.
A line divides the plane into two parts. Each part with this line is called a half‑plane.ma6609e8a4cfcab1b_1527752263647_0A line segment is the part of a straight line, located between two points, together with these points.
A point located on a straight line divides it into two parts. Each part with the point is called the ray.
A line divides the plane into two parts. Each part with this line is called a half‑plane.

Task

Students work individually, using computers. Their task is to change the location of the points in such a way as to obtain the line, the ray and the line segmentline segmentline segment.

[Geogebra applet]

Students answer the following questions:

Does the line have the beginning and the ending?

Where is the beginning of the given ray?

Are line segments AB and BA of the same length?

Task

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

Two straight lines are parallel, if they do not have any common points or have infinitely many common points (they overlap).
If the lines have exactly one point in common then we say that they intersect. We call them intersecting lines.
If two lines intersect at the right angle, we call them perpendicular.ma6609e8a4cfcab1b_1527752256679_0Two straight lines are parallel, if they do not have any common points or have infinitely many common points (they overlap).
If the lines have exactly one point in common then we say that they intersect. We call them intersecting lines.
If two lines intersect at the right angle, we call them perpendicular.

An extra task

Construct any straight linestraight linestraight line that is perpendicularperpendicularperpendicular to a line going through a pointpointpoint which is located on this line.

Task

Students revise what the polygonal chain is.
The polygonal chain is a figure made of line segments in such a way that the end of the first line segment is the beginning the second line segment, the ending of the second line segment is the beginning of the third line segment, etc.ma6609e8a4cfcab1b_1527712094602_0Students revise what the polygonal chain is.
The polygonal chain is a figure made of line segments in such a way that the end of the first line segment is the beginning the second line segment, the ending of the second line segment is the beginning of the third line segment, etc.

The ends of the line segments are the apexes of the polygonal chainpolygonal chainpolygonal chain.

Task

Draw any closed polygonal chain and an open polygonal chainpolygonal chainpolygonal chain.

Task

Draw two figures that are not polygonal chains.

Lesson summaryma6609e8a4cfcab1b_1528450119332_0Lesson summary

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

The line segmentline segmentline segment is the part of the straight linestraight linestraight line, located between two points, together with these points.

The point located on the straight linestraight linestraight line divides it into two parts. Each part with the pointpointpoint is called the ray.

The line divides the planeplaneplane into two parts. Each part with this line is called a half‑planehalf‑planehalf‑plane.

Two straight lines are parallel, if they do not have any common points or have infinitely many common points (they overlap).

If the lines have exactly one pointpointpoint in common then we say that they intersect. We call them intersecting linesintersecting linesintersecting lines.

If two lines intersect at the right angle, we call them perpendicularperpendicularperpendicular.

Selected words and expressions used in the lesson plan

figurefigurefigure

geometric figuresgeometric figuresgeometric figures

half‑planehalf‑planehalf‑plane

intersecting linesintersecting linesintersecting lines

line segmentline segmentline segment

perpendicularperpendicularperpendicular

planeplaneplane

pointpointpoint

polygonal chainpolygonal chainpolygonal chain

stright linestraight linestright line