Fourth Grade Math Perimeter

Introduction to fourth grade math perimeter:

In fourth grade math, perimeter of a shape is nothing but a path that surrounds an area of shape.

Learning math perimeters in fourth grade is an essential one.In this article of  fourth grade math perimeter, the perimeters of different math shapes related to fourth grade are calculated using the different formulas. In addition, practice problems are given for better understanding.

Formulas for Fourth Grade Math Perimeter:

Square:        Perimeter  = a + a + a +a

= 4 * a

a ---> side length

Rectangle:    Perimeter  = l + w + l + w

= 2l +2w

= 2 ( l +w )

Parallelogram: Let ‘a’ and ‘b’ are the side values of a parallelogram.

Perimeter  = a+b+a+b

= 2a+2b

= 2(a+b)

Equilateral triangle:  In the equilateral triangle, all the sides are equal.

Perimeter  =  a + a + a

= 3a

Example Problems for Perimeter:

Example 1:

Find the perimeter of rectangle with the length and width are 13 cm and 7 cm.

Solution:

Perimeter  = 2 ( l+ w )

= 2 ( 13 + 7 )

= 2 (20)

= 40 cm

Example 2:

Calculate the perimeter of equilateral triangle with the side length 15 cm

Solution:

Perimeter  = 3a

= 3*15

= 45 cm

Example 3:

Calculate the perimeter of Square having the side length of 19 cm.

Solution:

Perimeter  =  4 a

=  4 * 19

=  76 cm

Example 4:

Find the perimeter of parallelogram with the breadth and height are 14 cm and 9 cm.

Solution:

Perimeter  = 2 ( a+ b )

= 2 ( 14 + 9 )

= 2 (23)

= 46 cm

Practice Problems for Perimeter:

1) Find the perimeter of rectangle with the length and width are 21 mm and 8 mm.

Answer: 58 mm

2) Calculate the perimeter of equilateral triangle with the side length 22 mm

Answer: 66 mm

3) Calculate the perimeter of Square having the side length of 41cm.

Answer: 164 cm

4) Find the perimeter of parallelogram with the breadth and height are 32 cm and 13 cm.

Answer: 90 cm

5) Calculate the perimeter of equilateral triangle with the side length 8 mm

Answer: 24 cm