Concepts of Perimeter:
FOR CLASS 4TH AND 5TH
DEFINATION: PERIMETER is the length of the boundary of a plane figure.
FORMULAS:
1)Perimeter of the given shape = the sum of the length of all sides of the given shape.
2)Perimeter of a rectangle = 2*( L+B)
3)Perimeter of a square = 4*S
4)Perimeter of an equilateral triangle = 3*S
BASIC SUMS BASED ON PERIMETER LEVEL – 3
SESSION – 3
Q.1) Find the missing length:
SOLUTION: 1st part
Given that:
Length = L = 14cm
Breadth = B = ?
Perimeter of rectangle = 48
Perimeter of rectangle = P = 2*( L+B )
P = 2*( 14+B )
48/2 = 14 + B
24 = 14 + B
24 – 14 = B
10cm = B
SOLUTION: 2nd Part
Given that :
Side 1 = S1 = 9cm
Side 2 = S2 = 3cm
Side 3 = S3 = 6cm
Side 4 = S4 = x = ?
Perimeter = P = 25cm
Perimeter of the given shape = sum of the length of all the sides
25 = 9cm + 3cm + 6cm + x
25 = 18cm + x
25 – 18 = x
7cm = x
SOLUTION: 3rd Part
Given that :
Side 1 = S1 = 5cm
Side 2 = S2 = 4cm
Side 3 = S3 = x = ?
Perimeter = P = 16 cm
Perimeter of the given shape = sum of the length of all sides
16 = 5cm + 6cm + x
16 = 9cm + x
16 – 9 = x
7cm = x
SOLUTION: 4th Part
Given that :
Length = L = 3.5cm
Breadth = B = X = ?
Perimeter = P = 11.5cm
Perimeter of rectangle = P = 2*( L+B )
11.5cm = 2*( 3.5cm + x )
11.5/2 = 3.5 +x
5.75 = 3.5 +x
5.75 – 3.5 = x
2.25 = x
SOLUTION: 5th part
Given that :
Side 1 = S1 = X =?
Side 2 = S2 = 3.5cm
Side 3 = S3 = 5.75cm
Perimeter = P = 13.5cm
Perimeter of the given shape = the sum of the length of all the sides
13.5 = x + 3.5 + 5.75
13.5 =x + 9.25
13.5 – 9.25 = x
4.25 = x
SOLUTION: 6th Part
Given that :
Side = S
Each Side of equilateral triangle = ?
Perimeter = P = 19.5units
P = 3*S
19.5 = 3*S
19.5/3 =S
6.5units = S
SOLUTION : 7th part
Given that :
Side = S = ?
Perimeter of square is = P
P = 4 * S
12.8 = 4 * S
S = 12.8 /4
S = 3.4 m