Polygon and its types

1. Week 7
Virtual Teaching
Phase-II
Lesson code: 5M25

2. We will start our daily class by reciting dua for knowledge
RECITE IT WITH YOUR TEACHER

3. Contents
Introduction to
polygons
Introduction to
Quadrilateral
Finding perimeter
of a square
Finding length of
a side of square

4. Geometry is a branch of mathematics that deals with
shapes and figures.
Geometry explains how to build or draw shapes, measure
them, and compare them.
Geometry:
✓ Minimum 3 line segments make a
closed shape that is called Triangle.
A part of line with two end points.
Line Segment:

5. Polygon:
Poly means “many”
Gon means “angles”
Polygon are the closed flat
figures , made up of straight
lines, that have many
angles(vertices) in them.
Polygon are the closed shapes
having three(3) or more
sides(line segments).
OR
Triangle
3-sided polygon
Quadrilateral
4-sided polygon
Pentagon
5-sided polygon

6. 2D (2-Dimensional) Shapes
2D stands for 2-dimensional. 2-dimensional shapes are flat
and only have two dimensions: length and width.
They include squares, rectangles, circles, triangles, and
more.
IMPORTANT
A circle is also a plane figure but it is not considered a
polygon, because it is a curved shape and does not have
sides. Therefore, we can say,
ALL THE POLYGONS ARE 2D SHAPES BUT
NOT ALL THE TWO-DIMENSIONAL FIGURES ARE POLYGONS.

7. LIST OF POLYGON NAMES
DEPENDING ON THE NUMBER OF SIDES

8. Quadrilateral
A Quadrilateral is a polygon having a number of sides equal to four.

9. Quadrilateral
A Quadrilateral is a polygon having a number of sides equal to four.
SQUARE:
Square is a quadrilateral having four equal sides
and 4 right angles.
90° 90°
90° 90°
E
F G
H
Properties of Square:
• All sides are equal in measurement.
• All angles are of 90-degrees measurement.

10. Perimeter is the total length of
the boundary of any closed region.
Perimeter:
4 × length of a side of square
OR
length + length + length + length
Perimeter of a square:
Important notes about finding perimeter
The units to measure the perimeter are
m (meters) , cm (centimeters) etc

11. REAL LIFE SITUATIONS
DESCRIBING PERIMETER
The length of the fence around a
closed region
The total length of a photo frame
The length of hedge around a garden
The total length of constructing
boundary wall around a building

12. Derivation of formula of length of a side of square
which is used when perimeter of square is given.
As, Perimeter of a square = 4 × length of a side of square
𝑫𝒊𝒗𝒊𝒅𝒊𝒏𝒈 𝒃𝒐𝒕𝒉 𝒔𝒊𝒅𝒆𝒔 𝒃𝒚 𝟒
=
OR
4 × l = Perimeter of a square
Length of a side of square =
Perimeter of square
𝟒
OR
=

13. IMPORTANT

14. Perimeter of a square = 4 × length of a side of square
s
𝑻𝒐 𝒇𝒊𝒏𝒅 𝒑𝒆𝒓𝒊𝒎𝒆𝒕𝒆𝒓 𝒐𝒇 𝒔𝒒𝒖𝒂𝒓𝒆 𝒘𝒉𝒆𝒏 𝒊𝒕𝒔 𝒐𝒏𝒆 𝒔𝒊𝒅𝒆 𝒍𝒆𝒏𝒈𝒕𝒉 𝒊𝒔 𝒈𝒊𝒗𝒆𝒏
=
𝑻𝒐 𝒇𝒊𝒏𝒅 𝒔𝒊𝒅𝒆 𝒍𝒆𝒏𝒈𝒕𝒉 𝒐𝒇 𝒂 𝒔𝒒𝒖𝒂𝒓𝒆 𝒘𝒉𝒆𝒏 𝒊𝒕𝒔 𝒑𝒆𝒓𝒊𝒎𝒆𝒕𝒆𝒓 𝒊𝒔 𝒈𝒊𝒗𝒆𝒏

15. Do all classwork
questions on
rough notebook

16. Total length of the boundary = 38 cm
Perimeter = Total length of the boundary
Question#1:
Find the perimeter of a square shaped photo frame when the
total length of its boundary is 38cm.
Perimeter of square shaped photo frame is 38 cm
Perimeter of square shaped photo frame = 𝟑𝟖 𝒄𝒎
Solution:

17. Total length of the boundary wall = perimeter = ?
Length of one side = 27 m
Question#2:
Find the total length of a boundary wall around a square shaped
building when length of its one side is 27 m.
Total length of the square shaped boundary wall is 108 m
Perimeter of square = 4 × length of a side
= 4 × 27 m
=
Solution:

18. =
Solution:
Length of a side of the square = ?
Perimeter of the square = 56 cm
Question#3:
Find length of a side of a square whose perimeter is 56cm.
Length of a side of the square is 14 cm
=
1
14
length = 𝟏𝟒 𝒄𝒎

19. Recheck all solutions of classwork questions by yourself
through shared PDF
ALSO REVISE TODAY’S COMPLETE LECTURE
Do Live worksheet