Area of square = Side $\times$ Side
                      = 14 $\times$ 14
                      = 196 $c{m}^2$

Area of rectangular field
= length $\times$ breadth
= 12 $\times$ 5
= $60{\text{m}}^2$

Cost of ploughing
= Total area $\times$ cost per sq. metre 
= $60\times 12$
= ₹ 720

Perimeter of square = 4 $\times$ length of side
                             = 4 $\times$ 15
                             = 60 cm

Given a square room of side = 6 m.
Area of each tile = 0.5 m²  
We know that, area of a square = Side $\times$ Side
$\therefore$ Area of a square room
= 6 $\times$ 6 = 36 m².

So, number of tiles required
= $\frac{\text{Area of room}}{\text{Area of a single tile}}$
= $\frac{36}{0.5}$ = 72
Hence, Karan should buy 72 tiles to cover the floor of his room.

Area of the figure = Area of A + Area of B + Area of C
Area of rectangle $=length\times breadth$

A , B & C are rectangles  
$=3\times 6+4\times (6-3)+2\times 6$ 
$=(3\times 6)+(4\times 3)+(2\times 6)$
= $18+12+12=42sq.units$

Concept: 1 Mark
The perimeter is the distance covered along the boundary forming a closed figure when you go round the figure once.

Steps: 1 Mark
Answer: 1 Mark
Area of the field
= $10\times 2$
= $20f{t}^2$

Area covered by one bag of soil
=$10f{t}^2$
$\therefore$ No. of bags required
= $\frac{\text{Area of the field}}{\text{Area covered by one bag of soil}}=\frac{20}{10}=2$ 

Hence, Preeti need 2 bags.

Steps: 1 Mark
Answer: 1 Mark
Let the breadth of the notebook be $ycm$
Length = 15 cm (Given)
Perimeter = 50 cm (Given)
Perimeter of the rectangular notebook = Sum of the lengths of its four sides.

$\Rightarrow 50=15+15+y+y$

$\Rightarrow 50=2(15+y)$

$\Rightarrow 25=(15+y)$

$\Rightarrow y=10$

$\therefore$ The width of notebook is $10cm$
Area covered by the notebook
$=15cm\times 10cm$
$=150c{m}^2$

Pentagon: 1 Mark
Steps: 1 Mark
Answer: 1 Mark
Pentagon has 5 sides.

Given that each side of the pentagon $=30m$
The perimeter of a regular pentagon
= $5\times$ length of each side
= $5\times 30$
= $150m$
Hence, the distance covered by Shakshi is $150m.$

Steps: 1 Mark
Formula: 1 Mark
Answer: 1 Mark
Area of the living room
= length $\times$ breadth = $9m\times 9m=81m^2$
The cost per $m^2$  = ₹12
Cost for $81m^2=12\times 81=₹972$