Area = 5.5 × 3.75 sq. metre.

Cost for 1 sq. metre. = Rs. 800

Hence total cost = 5.5 × 3.75 × 800 = 5.5 × 3000 = Rs. 16500

We have: (l - b) = 23 and 2(l + b) = 206 or (l + b) = 103.
Solving the two equations, we get: l = 63 and b = 40.
Area = (l x b) = (63 x 40) = 2520 sq.m

Let inner radius be r metres. Then, 2 ?r = 440 ; r =  440 × 7 44= 70 m.

Radius of outer circle = (70 + 14) m = 84 m.

Let the breadth of the given rectangle be x then length is 2x.
thus area of the given rect is  2 x 2

after dec 5cm from length and inc 5cm breadth , new lenght becomes 2x-5 and breadth is x+5.thus new area =(2x-5)(x+5)= 2 x 2 + 5 x - 25

since new area is 75 units greater than original area thus
2 x 2 + 75 = 2 x + 5 x - 25
5x=75+25
5x=100
therefore x=20
hence length of the rectangle is 40 cm.

Let breadth=x meters.   Then, Length = 115 x 100 meters 

Given that,  x × 115 x 100 = 460  

=> x = 20  

Breadth = 20 

Circular piece is 4 x 11 = 44 cm long,

Then Circumference of circle is given by,

44 = pi x D, where D is the diameter

D = 44 / pi

Take pi = 22 / 7, then

D = 44 / (22/7) = (44 x 7) / 22

D = 14 cm.

required percentage = ?r 2 2 ?r × 100 = 250%

clearly the cow will graze a circular field of area 9856 sq m and radius equal to the length of the rope.

Let the length of the rope be r mts 

then,  ?r 2 = 9856 ? r 2 = 9856 × 7 22 = 3136 ? r = 56 m

Square units 13 by 9 of an office means office of length 13 units and breadth 9 units.

Now its area is 13x 9 = 117 square units or units square.

We know that, 

Area of trapezium = 1/2 x (Sum of parallel sides) x (Distance between Parallel sides)

= 1/2 x (12 + 10) x 14

= 22 x 14/2

= 22 x 7

= 154 sq. cm