Topicm03d9d672ef40ac16_1528449000663_0Topic

The perimeters of rectangles and squares

Levelm03d9d672ef40ac16_1528449084556_0Level

Second

Core curriculumm03d9d672ef40ac16_1528449076687_0Core curriculum

IX. Polygons and circles. The student:

4) recognises and identifies : the square, the rectangle, the rhombus, the parallelogram and the trapezium;

5) is familiar with the most important properties of the square, the rectangle, the rhombus, the parallelogram and the trapezium; recognises the figures symmetrical about the axis and indicates the symmetry axes of figures.

XI. Calculations in geometry. The student:

1) calculates the perimeter of the polygon with length of its sides given.

Timingm03d9d672ef40ac16_1528449068082_0Timing

45 minutes

General objectivem03d9d672ef40ac16_1528449523725_0General objective

Matching a mathematical model to a simple situation and using it in various contexts.

Specific objectivesm03d9d672ef40ac16_1528449552113_0Specific objectives

1. Calculating the perimeter of the rectangle.

2. Solving the task using the perimeter of the rectangle.

3. Communicating in English; developing mathematical and basic scientific, technical and digital competences; developing learning skills.

Learning outcomesm03d9d672ef40ac16_1528450430307_0Learning outcomes

The Student:

- calculates the perimeter of the rectangle (the square) with given sides,

- do the calculations connected to the perimeter of the rectangle in the practical situations.

Methodsm03d9d672ef40ac16_1528449534267_0Methods

1. Brainstorming.

2. Situational analysis.

Forms of workm03d9d672ef40ac16_1528449514617_0Forms of work

1. Individual work.

2. Class work.

Lesson stages

Introductionm03d9d672ef40ac16_1528450127855_0Introduction

The teacher introduces the topic of the lesson. The students are going to learn the method of calculating the rectanglerectanglerectangle and thesquaresquaresquare.

The students revise the notions of the rectangle and the square.

- the rectangle is the quadranglequadranglequadrangle with four right angles,

- the square is the rectangle with all equal sides.

Procedurem03d9d672ef40ac16_1528446435040_0Procedure

Task 1

The students work individually using their computers.

[Slideshow]

They are going to watch the method of calculating the perimeter of the rectanglerectanglerectangle.

The student draw the following conclusion:

- the perimeter of the rectangleperimeter of the rectangleperimeter of the rectangle is the sum of all its sides.

Task 2

The students draw the rectangle with the sides of 15 cm and 2 dm and calculate its perimeter.

After completing the task they come up with the following conclusion:

- to calculate the perimeter of the rectangleperimeter of the rectangleperimeter of the rectangle we should express the lengthlengthlength of its sides in the same units,
- the perimeter of the rectangle can be calculated using various methods, for example:

$L=15cm+20cm+15cm+20cm=70cm$

$L=2\cdot 15cm+2\cdot 20cm=30cm+40cm=70cm$

$L=2\cdot (15cm+20cm)=2\cdot 35cm=70cm$

Task 3

The students calculate the perimeter of the squaresquaresquare with the side of  5 cm. They give the following solutions:

$L=5cm+5cm+5cm+5cm$

or

$L=4·5 cm$

The students calculate the perimeter of the rectanglerectanglerectangle in the practical situation.

Task 4

The picture has got the dimensions of 60 cm by 80 cm. Calculate the length of the frame needed to frame this picture.m03d9d672ef40ac16_1527752256679_0The picture has got the dimensions of 60 cm by 80 cm. Calculate the length of the frame needed to frame this picture.

An extra task:

The rectangle was made of seven identical squares. How many times its diameter is bigger than the diameter of each square?

Lesson summarym03d9d672ef40ac16_1528450119332_0Lesson summary

Students do the exercises summarising the class.

Then, together they sum up the classes, drawing the conclusions to memorize:

- the perimeter of the rectangle is the sum of all its sides,
- the perimeter of the square is the sum of all its sides.m03d9d672ef40ac16_1527752263647_0- the perimeter of the rectangle is the sum of all its sides,
- the perimeter of the square is the sum of all its sides.

Selected words and expressions used in the lesson plan

rectanglerectanglerectangle

squaresquaresquare

lengthlengthlength

widthwidthwidth

diagonaldiagonaldiagonal

quadranglequadranglequadrangle

right angleright angleright angle

perpendicular sidesperpendicular sidesperpendicular sides

parallel sidesparallel sidesparallel sides

perimeter of the rectangleperimeter of the rectangleperimeter of the rectangle