Perimeter and Area | IT

Question 17

Now, find out the missing dimensions and area of Sharan's home. Below is the plan:

Some of the measurements are given.

a. Find the missing measurements.

b. Find out the area of his house.

What are the dimensions of all the different rooms in Sharan's house? Compare the areas and perimeters of Sharan's house and Charan's house.

Question diagram 1
Check your answer with HomiSolve it yourself, then let Homi check your steps and spot mistakes.
Solution

Let us find the missing measurements and areas of Sharan's house.

Step 1 — Find the total height of the house

Look at the left side of the house. The Master Bedroom is 15 ft high. The Small Bedroom is 10 ft high. The total height of the house is the sum of these heights.

=15 ft+10 ft= 15 \text{ ft} + 10 \text{ ft}

=25 ft= 25 \text{ ft}

Total height=25 ft\boxed{\text{Total height} = 25 \text{ ft}}

Diagram 1

Step 2 — Find the total area of the house

The total width of the house is given as 42 ft. The total height of the house is 25 ft (from Step 1). The area of the house is width multiplied by height.

=42 ft×25 ft= 42 \text{ ft} \times 25 \text{ ft}

=1050 sq ft= 1050 \text{ sq ft}

Total area of house=1050 sq ft\boxed{\text{Total area of house} = 1050 \text{ sq ft}}

Step 3 — Calculate Small Bedroom area

The dimensions of the Small Bedroom are 12 ft x 10 ft. The area is length multiplied by width.

=12 ft×10 ft= 12 \text{ ft} \times 10 \text{ ft}

=120 sq ft= 120 \text{ sq ft}

Small Bedroom Area=120 sq ft\boxed{\text{Small Bedroom Area} = 120 \text{ sq ft}}

Step 4 — Calculate Utility room dimensions and area

Look at the top right corner. The Kitchen is 10 ft high. The Utility room is next to it. So, the Utility room is also 10 ft high. The area of the Utility room is given as 70 sq ft. To find the width, we divide the area by the height.

Width=AreaHeight\text{Width} = \frac{\text{Area}}{\text{Height}}

=70 sq ft10 ft= \frac{70 \text{ sq ft}}{10 \text{ ft}}

=7 ft= 7 \text{ ft}

So, the Utility room dimensions are 7 ft x 10 ft. The area is 70 sq ft.

Utility: 7 ft×10 ft, Area=70 sq ft\boxed{\text{Utility: 7 ft} \times 10 \text{ ft, Area} = 70 \text{ sq ft}}

Diagram 2

Step 5 — Calculate Toilet dimensions and area

Look at the top section of the house. The total width is 42 ft. The Master Bedroom width is 12 ft. The Kitchen width is 18 ft. The Utility width is 7 ft (from Step 4). The Toilet is between the Master Bedroom and the Kitchen. Let us find the Toilet's width.

Toilet Width=Total Width(Master Bedroom Width+Kitchen Width+Utility Width)\text{Toilet Width} = \text{Total Width} - (\text{Master Bedroom Width} + \text{Kitchen Width} + \text{Utility Width})

=42 ft(12 ft+18 ft+7 ft)= 42 \text{ ft} - (12 \text{ ft} + 18 \text{ ft} + 7 \text{ ft})

=42 ft37 ft= 42 \text{ ft} - 37 \text{ ft}

=5 ft= 5 \text{ ft}

Now, let us find the Toilet's height. The Kitchen and Utility rooms are 10 ft high. The Toilet is next to the Kitchen and has the same top and bottom lines as the Kitchen. So, the Toilet's height is also 10 ft. The area of the Toilet is width multiplied by height.

=5 ft×10 ft= 5 \text{ ft} \times 10 \text{ ft}

=50 sq ft= 50 \text{ sq ft}

Toilet: 5 ft×10 ft, Area=50 sq ft\boxed{\text{Toilet: 5 ft} \times 10 \text{ ft, Area} = 50 \text{ sq ft}}

Diagram 3

Step 6 — Calculate Hall dimensions and area

Look at the bottom section of the house. The Hall is to the right of the Small Bedroom. The Small Bedroom is 10 ft high. It is below the Master Bedroom, which is 15 ft high. So, the Small Bedroom's top is 15 ft from the top of the house. Its bottom is 25 ft from the top. The Toilet, Kitchen, and Utility rooms are 10 ft high. Their bottom edge is 10 ft from the top of the house. The Hall is below the Toilet and Kitchen. Its top edge is 10 ft from the top of the house. Its bottom edge is at the bottom of the house, which is 25 ft from the top. So, the Hall's height is the difference between these distances.

Hall Height=25 ft10 ft\text{Hall Height} = 25 \text{ ft} - 10 \text{ ft}

=15 ft= 15 \text{ ft}

The Hall's width is given as 23 ft. The area of the Hall is width multiplied by height.

=23 ft×15 ft= 23 \text{ ft} \times 15 \text{ ft}

=345 sq ft= 345 \text{ sq ft}

Hall: 23 ft×15 ft, Area=345 sq ft\boxed{\text{Hall: 23 ft} \times 15 \text{ ft, Area} = 345 \text{ sq ft}}

Diagram 4

Step 7 — Calculate Entrance dimensions and area

Look at the bottom right corner. The Entrance is to the right of the Hall. The Hall's height is 15 ft (from Step 6). The Entrance is next to the Hall and has the same top and bottom lines. So, the Entrance's height is also 15 ft. Now, let us find the Entrance's width. The total width of the house is 42 ft. The Small Bedroom width is 12 ft. The Hall width is 23 ft (given). The Entrance is to the right of the Hall.

Entrance Width=Total Width(Small Bedroom Width+Hall Width)\text{Entrance Width} = \text{Total Width} - (\text{Small Bedroom Width} + \text{Hall Width})

=42 ft(12 ft+23 ft)= 42 \text{ ft} - (12 \text{ ft} + 23 \text{ ft})

=42 ft35 ft= 42 \text{ ft} - 35 \text{ ft}

=7 ft= 7 \text{ ft}

The area of the Entrance is width multiplied by height.

=7 ft×15 ft= 7 \text{ ft} \times 15 \text{ ft}

=105 sq ft= 105 \text{ sq ft}

Entrance: 7 ft×15 ft, Area=105 sq ft\boxed{\text{Entrance: 7 ft} \times 15 \text{ ft, Area} = 105 \text{ sq ft}}

Diagram 5

Step 8 — List all room dimensions and areas

We have found all the missing measurements. Master Bedroom: 12 ft x 15 ft, Area = 180 sq ft. Toilet: 5 ft x 10 ft, Area = 50 sq ft. Kitchen: 18 ft x 10 ft, Area = 180 sq ft. Utility: 7 ft x 10 ft, Area = 70 sq ft. Small Bedroom: 12 ft x 10 ft, Area = 120 sq ft. Hall: 23 ft x 15 ft, Area = 345 sq ft. Entrance: 7 ft x 15 ft, Area = 105 sq ft.

Let us check the total area by adding all room areas.

180+50+180+70+120+345+105180 + 50 + 180 + 70 + 120 + 345 + 105

=1050 sq ft= 1050 \text{ sq ft}

This matches the total area of the house we found in Step 2.

Step 9 — Find the perimeter of Sharan's house

The house is a large rectangle. Its total width is 42 ft. Its total height is 25 ft. The perimeter is 2×(width+height)2 \times (\text{width} + \text{height}).

=2×(42 ft+25 ft)= 2 \times (42 \text{ ft} + 25 \text{ ft})

=2×67 ft= 2 \times 67 \text{ ft}

=134 ft= 134 \text{ ft}

Perimeter of Sharan’s house=134 ft\boxed{\text{Perimeter of Sharan's house} = 134 \text{ ft}}

Step 10 — Compare areas and perimeters

The area of Sharan's house is 1050 sq ft. The problem states that Charan's house has the same area, 1050 sq ft. The perimeter of Sharan's house is 134 ft. The problem states that the perimeter of Charan's house is 130 ft. So, Sharan's house has a greater perimeter than Charan's house.

Answer

a. The missing measurements are as follows:

  • Master Bedroom: 12 ft × 15 ft, Area = 180 sq ft
  • Toilet: 5 ft × 10 ft, Area = 50 sq ft
  • Kitchen: 18 ft × 10 ft, Area = 180 sq ft
  • Utility: 7 ft × 10 ft, Area = 70 sq ft
  • Small Bedroom: 12 ft × 10 ft, Area = 120 sq ft
  • Hall: 23 ft × 15 ft, Area = 345 sq ft
  • Entrance: 7 ft × 15 ft, Area = 105 sq ft b. The area of his house = 25 ft × 42 ft = 1050 sq ft The area of Sharan's house and Charan's house are same and equal to 1050 sq ft. The perimeter of Sharan's house (134 ft) is greater than Charan's house (130 ft).

More questions in IT

Q1

Akshi says that the perimeter of this triangle shape is 9 units. Toshi says it can’t be 9 units and the perimeter will be more than 9 units. What do you think?

Q2

Write the perimeters of the figures below in terms of straight and diagonal units.

Q3

What is a similarity between a square and an equilateral triangle?

Q4

Split and rejoin

A rectangular paper chit of dimension 6 cm × 4 cm is cut as shown into two equal pieces. These two pieces are joined in different ways.

Find out the length of the boundary (i.e., the perimeter) of each of the other arrangements below.

Q5

Arrange the two pieces to form a figure with a perimeter of 22 cm.

Q6

In previous grades, we arrived at the formula for the area of a rectangle and a square using square grid paper. Do you remember?

Q7

Look at the figures below and guess which one of them has a larger area.

Q8

Find the area of the following figures.

Q9

Now, see the figures below. Is the area of the blue rectangle more or less than the area of the yellow triangle? Or is it the same? Why?

  • Can you see some relationship between the blue rectangle and the yellow triangle and their areas? Write the relationship here.
Q10

Use your understanding from previous grades to calculate the area of any closed figure using grid paper and—

  1. Find the area of blue triangle BAD.
Q11

Use your understanding from previous grades to calculate the area of any closed figure using grid paper and—

  1. Find the area of red triangle ABE.
Q12

Area of rectangle ABCD = ________

Q13

Using 9 unit squares, solve the following.

  1. What is the smallest perimeter possible?
  2. What is the largest perimeter possible?
  3. Make a figure with a perimeter of 18 units.
  4. Can you make other shaped figures for each of the above three perimeters, or is there only one shape with that perimeter? What is your reasoning?
Q14

Let's do something tricky now! We have a figure below having perimeter 24 units.

Without calculating all over again, observe, think and find out what will be the change in the perimeter if a new square is attached as shown on the right.

Q15

Experiment placing this new square at different places and think what the change in perimeter will be. Can you place the square so that the perimeter: a) increases; b) decreases; c) stays the same?

Q16

Below is the house plan of Charan. It is in a rectangular plot. Look at the plan. What do you notice?

Some of the measurements are given.

a. Find the missing measurements.

b. Find out the area of his house.

Q17

Now, find out the missing dimensions and area of Sharan's home. Below is the plan:

Some of the measurements are given.

a. Find the missing measurements.

b. Find out the area of his house.

What are the dimensions of all the different rooms in Sharan's house? Compare the areas and perimeters of Sharan's house and Charan's house.

Q18

Area Maze Puzzles

In each figure, find the missing value of either the length of a side or the area of a region.

← Back to Perimeter and Area