Class 4 Maths Chapter 9 Practice Question Answers - Perimeter and Area

Q1: Length of a rectangular park is 3 times its breadth. If the length of the park is 90 metres, then find the area of the park.
Ans: Length of rectangular park = 90m
So, the breadth = 90m / 3 = 30m.
Area of the rectangle = length x breadth
= 90m x 30m = 2700m²

Q2: Find the area of a rectangular cardboard 1 m long and 25 cm broad.
Ans: Length is in metres but the breadth is in cm. So, we change length into cm.
Thus, 1 m = 10 cm
So, Area = I x b
= 100 x 25 sq cm = 2,500 sq cm.

Q3: Find the area of a square with side 7 cm.
Ans: Area = side x side = 7 x 7 sq cm = 49 sq em.

Q4: Find the Perimeter (P) and the Area (A) of the Given Figures. Assume Each Side of the Unit Square is 2 Cm
Ans:
Each square is of length 2 cm.
Now perimeter means the continuous line forming the boundary of a closed geometry figure.
Now for perimeter of given figure;

As shown in figure; Perimeter of given figure = (2 + 2 + 2 + 2) + (2 + 2 + 2) + (2) + (2) + (2 + 2) + (2) + (2) + (2)
∴ Perometer of given figure = 28 cm
Now for Area; Area of one square = length × length
∴ Area of one square = 2 × 2
∴ Area of one square = 4 c m²
Now there are 8 square in given figure as shown below;
Therefore;
Area of given figure = area of one square × number of square
∴ Area of given figure = 4 × 8
∴ Area of given figure = 32c m²

Q5: Find the Perimeter of and Area of below Square:
Side = 30
Ans: Square means all side of quadrilateral are same.
A shown below square of 30 cm shown below.
Now, Perimeter of square = 30 + 30 + 30 + 30
∴ Perimeter of square = 120
Now, Area of square = side length × side length
∴ Area of square = 30 × 30
∴ Area of square = 900 cm²

Q6: Find the Perimeter and Area of below Rectangle
Length = 4m 20cm and Breadth = 2m and 50cm
Ans: First convert length and width in same unit.
For that; we know that 1 meter  100 cm.
Now for length 4 m 20 cm;
1m = 100cm
4m = ?
∴ = 400cm
Therefore Length = 400cm + 20cm = 420cm.
For width 2 m 50 cm;
1m = 100 cm
2 m = ?
∴ = 200 cm
Therefore Width = 200 cm + 50 cm = 250 cm
Now, for rectangle; Perimeter of Rectangle = 2 × ( Length + Width )
∴ Perimeter of Rectangle = 2 × ( 420 + 250 )
∴ Perimeter of Rectangle = 2 × ( 670 )
∴ Perimeter of rectangle = 1340 cm
Now for Area of rectangle; Area of rectangle = length × width
∴ Area of rectangle = 420 × 250
∴ Area of rectangle = 105000 cm²

Q7: Neha and Rekha Draw a Circle of Same Size in Their Books
If Length and Breadth of Neha՚s Book is 60 Cm and 40 Cm and Length and Breadth of Rekha՚s Book is 70 Cm and 30 Cm, Find Whose Book Have More Circle?
Ans: The size of Neha's book is 60 cm long 40 cm breadth.
Therefore the area of Neha's book
Area of nehaʹ s  book (Rectangular shape) = Length × Breadth
∴ Area of Neha book = 60 × 40
∴ Area of Neha book = 2400 cm² 
The size of Rekha's book is 70 cm long and 30 cm breadth.
Therefore the area of Rekha's book;
Area of Rekha's book (Rectangular shape) = Length × Breadth
∴ Area of Rekha's book = 70 × 30
∴ Area of Rekha's book = 2100 cm²
Therefore Area of Neha's book is greater than Rekha's book.
If they draw circle of same size in their book than Neha‘s book have more circle than Rekha’s book.

Q8: An Open Cinema Ground is 240 Meter Long and 190 Meter in Breadth
Find the area of land acquired by Open Cinema.
Ans: Length of an open cinema ground is 240 meter and breadth is 190 meter.
Means its rectangular shape.
Now for perimeter of Rectangle;
Area of open cinema ground = length × breadth
∴ Area of open cinema ground = 240 × 190
∴ Area of open cinema ground = 45600 m² 
Therefore the area of Open cinema ground is 45600 m².

Q9: Answer the Following Questions. (Every Room is a Square or a Rectangle)
(i) Look at the house design and find the area of the Bathroom room.
Ans: From figure; Area of Bathroom ( rectangular shape ) = length × breadth
∴ Area of Bathroom = 11 × 3
∴ Area of Bathroom = 33 cm²

(ii)  Look at the house design and find the area of the Kitchen room.
Ans: From figure; Area of kitchen room ( Rectangular shape ) = length × wreadth
∴ Area of kitchen room = 24 × 4
∴ Area of kitchen room = 96 m²

Q10: Find the length of Rectangular School playground of 4800 square meter area and 60 m breadth.
Ans: Area of rectangular shape school playground is 4800 square meter.
Breadth of rectangular shape play ground is 60 m.
Area of Rectangular shape play ground = Length × breadth
∴ 4800 = 60 × bredth
∴ Breadth of rectangle = 4800/60 = 80
Therefore Breadth of rectangle is 80 m.