# Architects design many types of buildings. They draw plans for houses, such as the plan shown in Fig. 9.68. An architect wants to install a decorative moulding around the ceilings in all the rooms. The decorative moulding costs 500/metre. What is the total cost of moulding for all the five rooms?

**Solution:**

The figure represents the plan for a house.

An architect wants to install decorative moulding around the ceilings in all the rooms.

The decorative moulding costs ₹500/metre.

We have to find the total cost of moulding for all the five rooms.

__Perimeter of rectangle__ = 2(length + breadth)

(i) Family room

Length = 4.57 m

Breadth = 5.48 m

Perimeter = 2(4.57 + 5.48)

= 2(10.05)

= 20.10 m

(ii) Dining room

Length = 5.41 m

Breadth = 5.48 m

Perimeter = 2(5.41 + 5.48)

= 2(10.89)

= 21.78 m

(iii) Bed room 1

__Perimeter of square__ = 4(side)

Side = 3.04 m

Perimeter = 4(3.04)

= 12.16 m

(iv) Bed room 2

Length = 3.04 m

Breadth = 2.43 m

Perimeter = 2(3.04 + 2.43)

= 2(5.47)

= 10.94 m

(v) Living room

Length = 3.81 m

Breadth = 7.53 m

Perimeter = 2(3.81 + 7.53)

= 2(11.34)

= 22.68 m

Total perimeter of all five rooms = 20.10 + 21.78 + 22.68 + 12.16 + 10.94

= 87.66 m

Cost of moulding 1 m = ₹500

Cost of moulding all five rooms = 87.66(500)

= ₹43830

Therefore, the total cost of moulding is ₹43830.

**✦ Try This: **A marble tile measure 10 cm×12 cm. How many tiles will be required to cover a wall of size 3 m × 4 m ? Also, find the total cost of the tiles at the rate of Rs 2 per tile.

**☛ Also Check: **NCERT Solutions for Class 7 Maths Chapter 11

**NCERT Exemplar Class 7 Maths Chapter 9 Problem 126 (c)**

## Architects design many types of buildings. They draw plans for houses, such as the plan shown in Fig. 9.68. An architect wants to install a decorative moulding around the ceilings in all the rooms. The decorative moulding costs 500/metre. What is the total cost of moulding for all the five rooms?

**Summary:**

Architects design many types of buildings. They draw plans for houses, such as the plan shown in Fig. 9.68. An architect wants to install decorative moulding around the ceilings in all the rooms. The decorative moulding costs 500/metre. The total cost of moulding for all the five rooms is ₹43830.

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