Area of Plane Figures - Class VI

area is measured in sq units..(cm x cm or mt x mt)

The amount of surface enclosed by a closed plane figure is called its 

Area can be expressed in square units.

Area is $2$ - dimensional.
Because it has length and width.

Amount of surface enclosed by a closed figure is called its area.

Yes the region covered by the enclosed figure or the total surface covered is the area of the particular shape.True.Option A

The measurement of area is done in square units.

Length of the boundary is the Perimeter not the area. The region enclosed inside the boundary is the area.
Therefore the statement is false.
Option B

The area of a flat, or plane figure is the number of unit squares that can be contained within it.

The amount of surface enclosed by a closed plane figure is called its area.

Let the length and breadth be 2x and 3x respectively. Then, floor area $= 6x^2$ sq.m. 
Cost of flooring at the rate of Rs. 4.00 per $m^2 = $ Rs. 216
$\therefore 6x^2 \times 4 = 216$
or $x^2 = 9$
or $x = 3$
$\therefore $ Length = 3x = 9m
Breadth = 2x = 6m
and Height $= \displaystyle \frac{1}{2} \times$ Length = 4.5 m
$\therefore $ Area of four walls = 2(length $\times$ height + breadth $\times$ height)
$=2 [9 \times 4.5 + 6 \times 4.5] = 135 m^2$

Area of a square = $side \times  side$
one side = 4 ft
Area = $4^2$
Area = $16$ $ft^2$

Given that, perimeter of rhombus is $100cm$ and one diagonal $40cm$

Perimeter of rhombus=4$\times $side

So side$=25cm$

And we know that in a rhombus diagonal divides rhombus in two eauilateral triangle.

Area of one triangle:- s$=(25+25+40)/2 =45$

So area=(s$\times $(s-a)$\times $ (s-b)$\times $(s-c))^1/2

= (45$\times $(45-40)$\times $(45-25)$\times $(45-25))^1/2

$= 300cm^2$

So total area is 300$\times $2=600cm^2

Hence, this is the answer.