Area Of Rectangle

PROJECT REPORT ON AREA & PERIMETER OF RECTANGLE Made By: Sh. Ram Lal (B.Sc. M.A. M.Ed.) Students Name: Sahil Kumar (6th) C

GOVT. MODEL HIGH SCHOOL, NABHA

PERIMETER OF RECTANGLE In our daily life we come across many situations where we need to find out regions occupied by different things and the length of their boundaries for example, to have an estimate of number of files required to cover a floor or to have estimate of the quantity of wood required for making a door. In this lesson we shall derive formula to find the perimeter of rectangle. The length of boundary of a simple closed curve is called perimeter.

Activities: - Measure two sides of the black board of your class room and find its perimeter by adding the length of sides. Find the perimeter of floor of your class room top of a bench or a Table we know that a rectangles a simple closed curve having tour sides where opposite sides are equal and each angle is 90. Rectangle abcd has been shown below. If its length is denoted by and breath by b. Then its sides were being shown in figure. D

l

b

C b

l A

B

Therefore perimeter of the rectangle (p) =ab+bc+cd+da l+b+l+b 2l+2b p=2(l+b) Thus perimeter of a rectangle = 2 (length breadth) Note:- Before using above formula, the length and breath should be converted into same units.

We can also find length and breadth as follows. Length of rectangle = perimeter /2-breath Breadth of a rectangle = perimeter/2-length. Example: - The length and breath of a rectangles are 12cm and 8cm respectively find its perimeter of rectangle = 2(length+breadth) Solution: 2(12cm+8cm) 2*20cm=40cm Example2 perimeter of a rectangle is 50cm and breath is 10cm find its length. Solution: - length of rectangle =perimeter/2-breath (50/2-io) cm =25-10cm =15cm Therefore length of the rectangle is 15cm

AREA OF RECTANGLE The curve together with its interior form a region and the measure (magnitude) of the region bounded By a curve is known as its area we want to know the quantity of seeds and fertilizers needed for a field we must know the area of the field. To cover a floor with tiles, to paint a wall or to paint the doors we need to measure their areas Standard limits of area For any kind of measurements, we require base units and we can measure a given quantity by comparing it with the base (standard) limits. We know that a rectangle is a simple closed curve having four sides where opposite sides is equal and each angle is 90. A rectangle abcd has been shown below. If its length is denoted by l and breath by b then its sides will be shown. In figure and area is denoted by a D b

l

C b

l A

B

Therefore the Area of the rectangle = length*breadth or A=lXb Note:- we should make sure before using above relation that the length and breath are expressed in the same limits . If the length and breadth are not in the same unit then the units of either of them should be converted that both are in the same units for above formula we can find length and breadth also as following: Length of a rectangle = area of the rectangle/ breadth of rectangle i.e. l = a/b And breadth of a rectangle = area of rectangle/length of rectangle i.e. b = a/l Activity Cut out some rectangle of different sizes from a piece of paper and find its area Example Find the area of rectangle whose length and breadth are as following Length = 6 cm Breadth = 3 cm Area of the rectangle = length x breadth = 6 cm x 3 cm = 18 cm

Example 2 Find the length of the rectangle whose are is 60 cm2 and breadth is 5cm Solution : Breadth of rectangle = area of rectangle/length of rectangle Breadth of rectangle = 60cm2/5cm = 12cm