What is perimeter ?
The perimeter is the length of the outline of the shape.
Formula for Perimeter of regular shape,
Perimeter of a triangle = a + b + c
(where a, b, and c are the length of its sides)
Perimeter of a rectangle = 2(length + Breadth)
Formula for Perimeter of irregular shape,
Perimeter = Sum of the length of all sides
Find the perimeter of each figure :
Problem 1 :
Solution :
By observing the figure, it is a triangle.
Perimeter of the triangle P = a + b + c
Here a = 14 in, b = 12 in and c = 18 in
= 14 + 12 + 18
Perimeter P = 44 in
Problem 2 :
Solution :
By observing the figure, it is a triangle.
Perimeter of the triangle P = a + b + c
Here a = 13 cm, b = 12 cm and c = 5 cm
= 5 + 13 + 12
Perimeter P = 30 cm
Problem 3 :
Solution :
By observing the figure, it is a rectangle.
Perimeter of the rectangle P = 2(l + b)
Here l = 7m, and b = 21m
= 2(7 + 21)
= 2(28)
Perimeter P = 56 m
Problem 4 :
Solution :
By observing the figure, it is a rectangle.
Perimeter of the rectangle P= 2(l + b)
Here l = 14 ft, and b = 19 ft
= 2(19 + 14)
= 2(33)
Perimeter P = 66 ft
Problem 5 :
Solution :
By observing the figure, it is a irregular shape.
Perimeter P = Sum of all the sides
= a + b + c + d
Here a = 19 yd, b = 18 yd, c = 16 yd, and d = 18 yd
= 19 + 18 + 16 + 18
Perimeter P = 71 yd
Problem 6 :
Solution :
By observing the figure, it is a trapezoid.
Perimeter of the trapezoid P = a + b + c + d
Here a = 17 m, b = 24 m, c = 17 m, and d = 29 m
= 17 + 24 + 17 + 29
Perimeter P = 87 m
Problem 7 :
Solution :
By observing the figure, it is a irregular shape.
Perimeter P = Sum of all the sides
= a + b + c + d + e + f
Here a = 4ft, b = 24 ft, c = 7 ft, d = 19 ft, e = 3 ft, and f = 5 ft
= 24 + 7 + 19 + 3 + 5 +4
Perimeter P = 62 ft
Problem 8 :
Solution :
By observing the figure, it is a irregular shape.
Perimeter P = Sum of all the sides
= a + b + c + d + e
Here a = 25 in, b = 10 in, c = 14 in, d = 7 in, e = 11 in
= 25 + 10 + 14 + 7 + 11
= 67 in
Problem 9 :
Find the perimeter of the square whose side is 2.5 cm.
Solution :
Side length of square = 2.5 cm
Perimeter of square = 4(side)
= 4(2.5)
= 10 cm
So, the perimeter of the square is 10 cm.
Problem 10 :
What will be the perimeter of a rectangle whose length is 2 m and breadth is 1.5 m ?
Solution :
Perimeter of rectangle = 2(length + width)
Length = 2 m and breadth = 1.5 m
= 2(2 + 1.5)
= 2(3.5)
= 7 m
So, the perimeter of the rectangle is 7 m.
Problem 11 :
Two squares of side 4 cm each are joined together to make a new figure. What is the figure called?
Solution :
Side length each square = 4 cm
When two squares are joined together, length of rectangle = 4 + 4 ==> 8 m
Width = 4 cm
Perimeter of rectangle = 2(8 + 4)
= 2 (12)
= 24 cm
So, the perimeter of the rectangle is 24 cm.
Problem 12 :
Find the perimeter of an equilateral triangle of side 9 cm
Solution :
Perimeter of equilateral triangle = 3(side)
Side length = 9 cm
= 3(9)
= 27 cm
Problem 13 :
Find the perimeter of a triangle of sides 3 cm, 4 cm and 5 cm.
Solution :
Let a, b and c are the side lengths of triangle.
a = 3 cm, b = 4 cm and c = 5 cm
Perimeter of triangle = 3 + 4 + 5
= 12 cm
Problem 14 :
Find the perimeter of an isosceles triangle whose equal sides are 8 cm each and third side is of 6 cm.
Solution :
Let a, b and c be three sides of triangle.
Here a and b be the equa l sides.
a = 8 cm = b and c = 6 cm
Perimeter of triangle = a + b + c
= 8 + 8 + 6
= 22 cm
Problem 15 :
Two sides of a triangle are 12 cm and 14 cm. If the perimeter of the triangle is 36 cm, find the third side.
Solution :
Let x be the third side of the triangle. The other sides are 12 cm and 14 cm.
Perimeter of triangle = 36 cm
12 + 14 + x = 36
26 + x = 36
x = 36 - 26
x = 10 cm
So, the third side is 10 cm.
May 21, 24 08:51 PM
May 21, 24 08:51 AM
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