Topicm7d6d3ea3fae842a3_1528449000663_0Topic

Polygons, their properties and types

Levelm7d6d3ea3fae842a3_1528449084556_0Level

Second

Core curriculumm7d6d3ea3fae842a3_1528449076687_0Core curriculum

VII. Lines and line segment. The student:

2) identifies perpendicular and parallel lines and line segments.

Timingm7d6d3ea3fae842a3_1528449068082_0Timing

45 minutes

General objectivem7d6d3ea3fae842a3_1528449523725_0General objective

Using mathematical objects, interpreting mathematical concepts.

Specific objectivesm7d6d3ea3fae842a3_1528449552113_0Specific objectives

1) Introducing the concept of the polygonPolygonpolygon, distinguishing polygons based on their properties.

2) Drawing polygons of given properties.

3) Communicating in English, developing basic mathematical, computer

and scientific competences, developing learning skills.

Learning outcomesm7d6d3ea3fae842a3_1528450430307_0Learning outcomes

The student:

- identifies polygons based on their properties,

- draws polygons of given properties.

Methodsm7d6d3ea3fae842a3_1528449534267_0Methods

1) Educational game.

2) Situational analysis.

Forms of workm7d6d3ea3fae842a3_1528449514617_0Forms of work

1) Individual work.

2) Group work.

Lesson stages

Introductionm7d6d3ea3fae842a3_1528450127855_0Introduction

Students prepare the information about tangramTangramtangram.

Tangram is a puzzle from China that is about 3000 years old. It consists of seven flat shapes, called tans, which form a square together. The aim of the game is to form a specific shape while using all the elements.m7d6d3ea3fae842a3_1527752263647_0Tangram is a puzzle from China that is about 3000 years old. It consists of seven flat shapes, called tans, which form a square together. The aim of the game is to form a specific shape while using all the elements.

Task
Students work in groups. The teacher gives out the templates of the tangramTangramtangram. Their task is to form the shapes they drew before.

Procedurem7d6d3ea3fae842a3_1528446435040_0Procedure

Task
Students work individually, using computers. Their task is to form the tangramTangramtangram according to the instruction presented in the applet.

[Geogebra applet]

The teacher informs students that parts of the tangramTangramtangram and figures they obtained are polygons. Together they analyse the shapes of tans and the figures they formed. They identify their common characteristics.

[Conclusion]

[Illustration 1]

- A polygonPolygonpolygon is a figure that consists of a part of the plane restricted by the polygonal chainPolygonal chainpolygonal chain, together with this polygonal chainPolygonal chainpolygonal chain.
- The sides of the polygonal chainPolygonal chainpolygonal chain are the sides of the polygonPolygonpolygon. The vertexes of the polygonal chainPolygonal chainpolygonal chain are the vertexes of the polygonPolygonpolygon.
- Points A, K, L, E, M are the vertexes of the polygonPolygonpolygon.
- Line segments AK, KL, LE, EM, MA are the sides of the polygonPolygonpolygon.
- Angles AKL, KLE, LEM, EMA, MAK are the interior angles of the polygonPolygonpolygon.
- The name of the polygonPolygonpolygon depends on the number of its angles.
- A polygonPolygonpolygon that has three angles is a triangleTriangletriangle. A polygonPolygonpolygon that has four angles is a tetragonTetragontetragon. A polygonPolygonpolygon that has five angles is pentagonPentagonpentagon, etc.

Task
Students draw polygonPolygonpolygon ABCDEF. They identify its type, give the vertexes, sides and angles.

Task
The teacher draws a rectangle. Students’ task is to find and name the following figures:
a) four triangles
b) a tetragonTetragontetragon
c) a pentagonPentagonpentagon

[Illustration 2]

Task
Students draw polygons of the following properties:

a) a tetragonTetragontetragon in which one of the interior angles is the right angle,
b) a polygonPolygonpolygon that has five vertexes and two pairs of parallel sides,
c) a triangleTriangletriangle that has an obtuse angle,
d) a hexagonhexagonhexagon that has two pairs of perpendicular sides.

An extra task
Students draw a pentagonPentagonpentagon that has two right angles, two parallel sides and two equal sides.

Lesson summarym7d6d3ea3fae842a3_1528450119332_0Lesson summary

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

- A polygonPolygonpolygon is a figure that consists of a part of the plane restricted by the polygonal chainPolygonal chainpolygonal chain, together with this polygonal chainPolygonal chainpolygonal chain.
- The sides of the polygonal chainPolygonal chainpolygonal chain are the sides of the polygonPolygonpolygon. The vertexes of the polygonal chainPolygonal chainpolygonal chain are the vertexes of the polygonPolygonpolygon.
- The name of the polygonPolygonpolygon depends on the number of its angles.
- A polygon that has three angles is a triangleTriangletriangle. A polygonPolygonpolygon that has four angles is a tetragonTetragontetragon. A polygonPolygonpolygon that has five angles is pentagonPentagonpentagon, etc.

Selected words and expressions used in the lesson plan

tangramTangramtangram

polygonal chainPolygonal chainpolygonal chain

sideSideside

vertexVertexvertex

polygonPolygonpolygon

triangleTriangletriangle

tetragonTetragontetragon

pentagonPentagonpentagon

hexagonhexagonhexagon