Question

"Question 2 Mrs. Kaushik has a square plot with the measurement as shown in the following figure. She wants to construct a house in the middle of the plot. A garden is developed around the house. Find the total cost of developing a garden around the house at the rate of Rs 55 per m2.

Class 8 Mensuration Page 171"

Answer 1

Mensuration:

Mensuration is the branch of mathematics which concerns itself with the measurement of Lengths, areas & volume of different geometrical shapes or figures.

Plane Figure: A figure which lies in a plane is called a plane figure.

For e.g:  a rectangle, square, a rhombus, a parallelogram, a trapezium.

 

Perimeter:

The perimeter of a closed plane figure is the total length of its boundary.

In case of a triangle or a polygon the perimeter is  the sum of the length of its sides.

Unit of perimeter is a centimetre  (cm), metre(m) kilometre(km) e.t.c

Area: The area of the plane figure is the measure of the surface enclose by its boundary.

 

The area of a triangle are a polygon is the measure of the surface enclosed by its sides.

A square centimetre (cm²) is generally taken at the standard unit of an area. We use square metre (m²) also for the units of area.

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Solution:

Answer is in the attachment..

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Hope this will help you...

Answer 2

Given:

• Side of a square plot = 25 m
• Length of the house = 20 m
• Breadth of the house = 15 m

To Find:

The total cost of developing a garden around the house at the rate of Rs 55 per $m^{2}$.

Formula:

Area of a square plot = square of a side = $(side)^{2}$

Solution:

Side of a square plot = 25 m

Area of a square plot = square of a side = $(side)^{2}$

$:\implies (25)^{2} = 625$

Therefore, area of a square plot is $625\: m^{2}$

Breadth of the house = 15 m

∴ Area of a square = Length × Breadth

$:\implies 20 \times 15 = 300 \: m^{2}$

Area of a garden = Area of a square plot - Area of a house

$:\implies 625 -300 = 325 \: m^{2}$

∵ Cost of developing the garden per sq. m $\implies Rs. 55$

∴  Cost of developing the garden 325 sq. m = Rs. 55 × 325

$:\implies \boxed{Cost \: of \: developing \: garden \: is \: Rs. 17875}$

Hence,

Cost of developing a garden is Rs. 17,875