Steps: 2 Marks
Formula: 1 Mark
Answer: 1 Mark
Area of one square tile = (side)${}^2$ = (0.5m)${}^2$ = 0.25 m${}^2.$

Area of the kitchen shelf  = length $\times$ breadth
= 4 $\times$ 3 = 12m
 

Number of tiles
= $\frac{\text{Area of kitchen shelf}}{\text{Area of square tile}}$
= $\frac{12}{0.25}$ = 48
Cost of 1 tile = Rs 70
Cost of 48 tiles = Rs 48 $\times$ 70 = Rs 3360

Steps: 2 Marks
Formula: 1 Mark
Answer: 1 Mark

Area of the above shapes can be calculated in two steps:
 

i) Area of shape marked 1
ii) Area of shape marked 2

$⇒$ Area of shape marked 1 = Area of rectangle
= length $×$ breadth

= 4 $×$ 9

= 36 cm${}^2$
 

$⇒$Area of shape marked 2 = Area of triangle
= $\frac{1}{2}×$ base $×$ height

= $\frac{1}{2}×$ 6 $×$ 4

= 12 cm${}^2$

$⇒$Area of shape = Area of shape marked 1+ Area of shape marked 2

= (36 + 12) cm${}^2$
= 48 cm${}^2$

Steps: 1 Mark
Formula: 1 Mark
Answer: 1 Mark
The perimeter of a regular hexagon
= $6\times sidelength$

Perimeter of the hexagon
= $6\times 45feet$
$=270feet$

As they walk 2 rounds:
$\therefore$  Distance covered
= $2\times 270feet$
$=540feet$

Steps: 2 Marks
Formula: 1 Mark
Answer: 1 Mark
Circumference of a circle
= $2\times \pi \times r=d\times \pi =88inches$
Where, d = diameter  and $\pi =\frac{22}{7}$
$\Rightarrow 88=\frac{22}{7}\times d$
$\Rightarrow d=\frac{88\times 7}{22}$
$\Rightarrow d=28inches$
The diameter of the pizza will be equal to the length of the side of the box.
Side of box = 28 inches
Area of the box = (side)${}^2$  = (28 inches)${}^2$ = 784 inches${}^2$

Each Option: 2 Marks
(a) The above figures can be split into multiple rectangles as follows:

Area of 1st rectangle
$=21×7=147\text{Â}c{m}^2$
Area of 2nd rectangle
$=7×7=49\text{Â}c{m}^2$
Area of 3rd rectangle
$=7×7=49\text{Â}c{m}^2$
Total area of the whole figure
 $=147+49+49=245\text{Â}c{m}^2$
(b) The above figures can be split into multiple rectangles as follows:

Area of 1st rectangle
$=5×1=5\text{Â}c{m}^2$
Area of 2nd rectangle
$=4×1=4\text{Â}c{m}^2$
Total area of the whole figure
$=5+4=9\text{Â}c{m}^2$

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

Hence, perimeter is the distance covered along the boundary forming a closed figure when you go round the figure once. 

The perimeter of a figure is the sum of lengths of all sides. In other words, perimeter is the distance covered along the boundary of the figure when you go round the figure once.

Perimeter of a rectangle
= 2 $\times$ (Length + Breadth)
= 2 $\times$ ( 10 inches + 5 inches )
= 30 inches.

Perimeter is basically the total length of the boundary of a figure. This is valid for closed figures only (both regular and irregular).

Perimeter = Sum of all the sides
Since it is a regular octagon, all sides will be equal.
$\therefore$ Perimeter = 8 $\times$ length of a side
                     = 8 $\times$ 15 cm
                     = 120 cm