4th standard chapter 1 question answer

 

 

MATHEMATICS

ENGLISH MEDIUM 

4 

FOURTH STANDARD

PART-1

CHAPTER-1

Perimeter And Area Of Simple

Geometrical Figures

 

 

Chapter - 1

Perimeter and area of

simple geometrical figures

The sum of length of all the sides of

 a geometrical figure is called its perimeter.

Exercise:  1.1

Ⅰ Find the perimeter of following

 geometrical figures.

                        1.

 

Ans:   given EF=3CM, FG=5CM,

GH=7CM, HI=5CM, IE=4CM.

Perimeter    =    EF + FG + GH + HI + IE

=   3CM + 5CM + 7CM + 5CM + 4CM

=   24CM

                      2.

Ans:  given JK=8CM, KL=6CM, LM=6CM,

 MN=5CM, NJ=2CM.

Perimeter   =   JK + KL + LM + MN + NJ

=   8CM + 6CM + 6CM + 5CM + 2CM

=   27CM

 

                3.

 

Ans:  given PQ=4CM, QR=2CM, RS=2CM,

 ST=4CM, TU=3CM, UP=3CM.

Perimeter   =   PQ + QR + RS + ST + TU + UP

=   4CM + 2CM + 2CM + 4CM + 3CM +3CM

=   18CM

                  4.

 

Ans:  given WX=7CM, XC=8CM, CN=4CM,

NR=6CM, RM=3CM, MW=2CM.

Perimeter   =   WX + XC + CN + NR + RM + MW

=   7CM + 8CM + 4CM + 6CM + 3CM + 2CM

=   30CM

Ⅱ In list ‘A’ plane figure and in list ‘B’ their

 perimeter are given. Match list ‘A’ with list ‘B’:

 

 

A	B	Answer
1)	a)      20cm	e)   18cm
2)	b)      15cm	a)      20cm
3)	c)   24cm	b)    15cm
4)	d)       22cm	b)        24cm
	e)       18cm

 

Exercise1. 2

1)	Observe the given figure.If its perimeter  is 24 cm, then what is the length  of the fourth side (QS)?	Perimeter = 24cm PQ=10CM, RS= 10CM, PR= 2CM, QS=? Sum of given side = PQ + RS+ PR = 10CM + 10CM + 2CM = 22CM Length of the four side = perimeter - sum of given side = 24cm – 22cm = 2cm QS =2CM.
2)	In the figure, the measurements of         four sides are given. If the perimeter is   24cm, then find the length of remaining side.	Perimeter=24cm AE= 3CM, EB= 4CM, CD= 8CM, AC= 4CM, BD=? Sum of all side = AE + EB + CD + AC = 3CM + 4CM + 8CM + 4CM = 19CM Length of the five side = perimeter -sum of all sides = 24cm - 19cm = 5cm BD = 5CM.
3)	In the figure the length of one side is 7cm.  if all the side are equal, then find its  perimeter.	Perimeter = 7cm + 7cm + 7cm + 7cm =28cm KLMN = 28CM.

 

The space or the region bound by a given

 closed figure is called its area.

In general area is expressed in square unit.

Exercise 1.3

                   I            On the graph sheet given, the area of each square 

         is 1 sq cm. Find the area of the given shapes.

1)		Totally there are 5 squares.   Area of given shape = 5 sq cm
2)		Totally there are 21 squares.   Area of given shape = 21 sq cm
3)		Totally there are 20 squares.   Area of given shape = 20 sq cm
4)		Totally there are 16 squares.   Area of given shape = 16 sq cm
5)		Totally there are 12 squares.   Area of given shape = 12 sq cm