CBSE Class 4 Maths Area And Perimeter Worksheet

CHAPTER : 9 AREA AND PERIMETER

Fill in the blanks

Question 1. The distance around the edge of a figure is called its __________.
Answer: perimeter
In simple words: The total length of the outer boundary of any closed shape is its perimeter.

Exam Tip: Remember that perimeter is a 1-dimensional measurement of length around a shape, so its units are simple units like cm or m.

Question 2. __________ is the amount of surface a figure covers.
Answer: Area
In simple words: Area measures the total flat space inside a closed boundary.

Exam Tip: Area is always expressed in square units (such as square cm or \(\text{cm}^2\)) because it measures 2-dimensional space.

Question 3. The unit of area is __________.
Answer: square centimetre (or square metre)
In simple words: Standard units used to measure area include square cm or square m.

Exam Tip: Always write the word 'square' before the unit or use the exponent 2 (e.g., \(\text{m}^2\)) when writing the unit of area.

Do the following

Question 1. Find the perimeter of the following
Answer:
For the first shape (irregular polygon with sides 5 cm, 2 cm, 3 cm, 3 cm, 2 cm, 2 cm):
Perimeter = \(5\text{ cm} + 2\text{ cm} + 3\text{ cm} + 3\text{ cm} + 2\text{ cm} + 2\text{ cm} = 17\text{ cm}\)

For the second shape (regular hexagon with each side 2 cm):
Perimeter = \(6 \times 2\text{ cm} = 12\text{ cm}\)

For the third shape (triangle with sides 3 cm, 3 cm, and 4 cm):
Perimeter = \(3\text{ cm} + 3\text{ cm} + 4\text{ cm} = 10\text{ cm}\)
In simple words: Add the lengths of all outer sides together to find the total perimeter of each shape.

Exam Tip: Count the number of outer sides carefully so that you do not leave out any side length while adding.

Question 2. Find the missing length.
a) Perimeter = 27 cm (Quadrilateral with sides 7 cm, 9 cm, 5 cm, and missing side ?)
Answer:
Sum of known sides = \(7\text{ cm} + 9\text{ cm} + 5\text{ cm} = 21\text{ cm}\)
Missing side = \(27\text{ cm} - 21\text{ cm} = 6\text{ cm}\)
In simple words: Subtract the sum of the given sides from the total perimeter to find the missing side length.

Exam Tip: Always verify your answer by adding all sides back together to check if they equal the given perimeter.

Question 2. b) Perimeter = 22 cm
Answer:
Sum of known sides = \(9\text{ cm} + 10\text{ cm} = 19\text{ cm}\)
Missing side = \(22\text{ cm} - 19\text{ cm} = 3\text{ cm}\)
In simple words: Subtract the known two sides of the triangle from the total perimeter to get the third side.

Exam Tip: Ensure all measurements are in the same unit before performing addition or subtraction.

Question 2. c) Perimeter = 41 cm
Answer:
Sum of known sides = \(15\text{ cm} + 5\text{ cm} + 12\text{ cm} + 3\text{ cm} = 35\text{ cm}\)
Missing side = \(41\text{ cm} - 35\text{ cm} = 6\text{ cm}\)
In simple words: Add all the outer side lengths that are given, then subtract that sum from 41 cm.

Question 3. Look at the pictures to answer the questions.
a) How far would you go if you jog around the school once? Twice?
Answer:
Perimeter of the rectangular school ground = \(2 \times (\text{length} + \text{breadth})\)
Length = 100 m, Breadth = 50 m
Perimeter = \(2 \times (100\text{ m} + 50\text{ m}) = 2 \times 150\text{ m} = 300\text{ m}\)
Distance around the school once = 300 m
Distance around the school twice = \(2 \times 300\text{ m} = 600\text{ m}\)
In simple words: Find the perimeter once for one round, and multiply by 2 for two rounds.

Exam Tip: When calculating distance around a shape, always calculate the perimeter first.

Question 3. b) How much fencing will be needed for this garden?
Answer:
The garden is a pentagon with side lengths 12 m, 12 m, 15 m, 12 m, and 13 m.
Fencing needed = Perimeter of the pentagon
Perimeter = \(12\text{ m} + 12\text{ m} + 15\text{ m} + 12\text{ m} + 13\text{ m} = 64\text{ m}\)
In simple words: Fencing requires covering the entire boundary, so add all outer side lengths together.

Exam Tip: Fencing problems always ask for the perimeter of the given land or garden.

Question 4. What area does each design cover?
Answer:
Refer text book exercises - Page 169 to 171.
In simple words: Count the unit squares or use the textbook grid method to find the area of the given designs as instructed in your textbook.

Exam Tip: When finding area using grid paper, count full squares as 1 and half squares (or more than half) according to your textbook rules.