It's about finding area and perimeter of some basic shapes.

2. • Introduction
• Formulae
• Solving sums
• HOT Questions

3. • P e r i me t e r :
P e r i me t e r i s t h e
d i s t a n c e a r o u n d a 2D
s h a p e . L i k e i n t h e
f o l l o wi n g s h a p e t h e
d i s t a n c e o f t h e b o r d e r
o r t h e s h a d e d p o r t i o n
i s t h e Pe r i me t e r .

4. • Ar e a :
A r e a i s t h e i n n e r
s u r f a c e o f a s h a p e
o r t h i n g , i t i s
u s u a l l y a 2D s h a p e .
L i k e i n t h e
f o l l o wi n g s h a p e t h e
s h a d e d p o r t i o n i s
Area
t h e Ar e a o f t h e
s h a p e .

5. • I n t h i s p r e s e n t a t i o n we
wi l l l e a r n a b o u t t h e
f o l l o w i n g sPhea rp ie m : t e
s e
r i s
1. R e c t a n g l e
a l wa y s
2.S q u a r e e x p r e s s e
3.P a r a l l e l o gdr ai m U n i t
n
4.T r i a n g l e a n d a r e a
5.C i r c l e i n U n i t 2.
We w i l l l e a r n a b o u t t h e
a r e a a n d p e r i me t e r .

6. Re c t a Re c t a
n g l e
 P e r i me t en : l e
r g me a n s
m e a n s , L +B +L +B f o u r
5 cm s i d e
s h a p e
wh i c h
2 cm 2 cm
h a s
o p p o s
i t e
Perimeter is 2 x (5+2) = 14 cm 5 cm s i d e s
e q u a l .
Ar e a :
5 cm
Area is 5 x 2 2 cm 2 cm
= 10 cm2
5 cm

7. Sq u a r e Sq u a r e
i s a
• P e r i me t e r : , me a snh s p e
a
S +S +S +S . l i k e
r e c t a n g
2 cm
l e
wh i c h
Perimeter is 4 x 2 h a s a l l
2 cm 2 cm
s i d e s
= 8 cm e q u a l .
2 cm
2 cm
• Ar e a : 2 cm 2 cm
Area is 2 x 2 = 4 cm2
2 cm

8. P a r a l l e l o g r aA m a l
p a r l e
• P e r i me t e r : l o g r a m
i s a
, m e a n 5 s S +B +S +B .
cm s h a p e
wh i c h
h a s
o p p o s i t
3 cm
3 cm e s i d e s
p a r a l l e
Perimeter is l a n d
5 cm e q u a l .
2 x (5+3) = 16 cm
5 cm
• Ar e a :
3 cm
Area is 5 x 3
= 15 cm2 Altitude
5 cm

9. Tr i a n g l e I t
s h
i s a
a p e
wh i c h h a s
• P e r i me t e r : 3 s i d e s
c l o s e d .(i t
i s h a l f o f
a
3 cm 4 cm a
p r a l l e l o
Perimeter is g r a m.
3+4+2 = 9 cm
2 cm
• Ar e a :
3 cm
Area is
½ x 4 x 3 = 6 cm2 4 cm

10. Ci r c l e i s a
Ci r c l e s h a p e
wh i c h h a s
• P e r i me t e r : n o e d g e a n d
h a s a
Ce n t r e
p o i n t ,
d i a me t e r ,
Perimeter is r a d i u s (h a l
4 cm
f o f
3.14 x 4 = 12.56 cm d i a m e t e r ),
e t c .
• Ar e a :
3 cm
Area is 3.14 x 32

11. • A rectangular field is 45 m long 20 m wide, a person ran around it. How much
did he run?
Length of the field = 45 m
Breadth of the field = 20 m
Therefore, Perimeter = 2 (45+20) m = 2 x 65 m = 130 m
Ans: He covered 130 m
• A rectangular field is 10 m long and 7 m wide. What is the area of the field?
Length of the field = 10 m
Breadth of the field = 7 m
Therefore, Area = 10 x 7 m 2 = 70 m2
Ans: The area is 70 m 2 .

12. • Find the perimeter of the square which has the sides of 2 cm.
Side of the square = 25 cm
Therefore the perimeter = 25 x 4 = 100 cm
Ans: The perimeter is 100 cm.
• Find the area of the square which has the side of 7 cm.
Side of the square = 7 cm
Area of the square = 7 x 7 cm 2 = 49 cm2
Ans: The area is 49 cm2

13. • Find the perimeter of a parallelogram which has the sides of 15 and
10 cm.
Parallel sides of the parallelogram = 15 cm
Parallel sides of the parallelogram = 10 cm
Therefore, perimeter = 2 x (10+15) = 2 x 25 = 50 cm
Ans: The perimeter is 50 cm.
• Find the area of a parallelogram which has altitude of 14 cm and base
of 20 cm.
Altitude of the parallelogram = 14 cm
Base of the parallelogram = 20 cm
Therefore area = 14 x 20 = 280 cm 2
Ans: Area of the parallelogram is 280 cm2

14. • An equilateral triangle has sides of 36 cm. A person rolled around a
wire around it. What is the length of the wire?
Length of the side of the equilateral triangle = 36 cm
Therefore, perimeter = 36 x 3 = 108 cm
Ans: The length of the wire is 108 cm.
• A triangle has a base of 10 cm and has the altitude of 15 cm. Find the
area of the triangle.
Base of the triangle = 10 cm
Altitude of the triangle = 15 cm
Therefore, Area = ½ x 10 x 15 = 75 cm 2
Ans: The area is 75 cm 2.

15. • Amit has a circular disc. He measured the radius which is 8 cm. What
is the circumference of the circle.
Diameter of the circle = 8 x 2 = 16 cm
Therefore, perimeter is 3.14 x 16 = 50.24 cm
Ans: The circumference is 50.24 cm.
• Rajan has a wheel which has diameter of 10 cm. He wants cover it
with a flat cover. For that he needs to find the area. What is the area?
Radius of the wheel = 10/2 = 5 cm
Therefore, area = 3.14 x 5 x 5 = 78.5 cm 2
Ans: The area is 78.5 cm 2

16. • A man wants to fence around this shaped field. His brother wants put grass in that field.
Cost of the fencing is Rs. 10 / m and cost of putting grass is Rs. 7 / m 2 . Which costs
more?
Fencing: Perimeter is 2+7+7+4+10 cm
= 30 cm
7m
Therefore, the cost is Rs. 30 x 10
= Rs 300 is cost of fencing.
Putting grass: Area of the square 7x 7 7m
4m
= 49 m2
Area of the rectangle 4 by 3 m 10 m
= 4 x 3 = 12 m 2
Area of the triangle = ½ x 3 x 3 = 4.5 m 2
Total area is 49+12+4.5 m 2 = 65.5 m2
Cost is Rs. 7 x 65.5 = Rs. 458.5
Ans: Putting grass is more costly.

17. • A square has a same area of a triangle. The side of the square is x, and base
of the triangle is also x, what will be the altitude of the triangle?
The area of the triangle = xxx
Therefore, let the altitude be a
ATQ
X x a x ½ = x2
a x ½ = x2 / x
a=xx2
a = 2x
Ans: the altitude is 2x

18. • A parallelogram has a altitude of 10 cm . And a circle has a area
of equal to the area of the parallelogram. The circle also has the
diameter of 10 cm. find the base of the parallelogram.
Area of the parallelogram = Area of the Circle
Therefore, Area of the circle = 3.14 x r x r
Radius = 10/2 = 5 cm
Therefore area = 3.14 x 5 x 5 = 3.14 x 25 = 78.5 cm 2
Therefore base of the parallelogram = 78.5/10 = 7.85 cm
Ans: The base is 7.85 cm