A rectangle is a four-sided polygon with opposite sides of equal length and all angles equal to 90 degrees. The perimeter of a rectangle is the total distance around its outer boundary. In this post, we will discuss how to find the perimeter of a rectangle and provide some examples.
Formula for Perimeter of Rectangle
The perimeter of a rectangle is the sum of the lengths of all its sides. If the length of the rectangle is l and its width is w, then the perimeter can be calculated using the following formula:
Perimeter = 2l + 2w
This formula simply adds up the lengths of the two pairs of opposite sides of the rectangle.
Example 1: Find the perimeter of a rectangle whose length is 12 cm and width is 8 cm.
Solution: Given, l = 12 cm and w = 8 cm Using the formula, Perimeter = 2l + 2w = 2(12) + 2(8) = 24 + 16 = 40 cm Therefore, the perimeter of the rectangle is 40 cm.
Example 2: The perimeter of a rectangle is 50 cm and its length is 16 cm. Find its width.
Solution: Given, Perimeter = 50 cm and l = 16 cm Using the formula, Perimeter = 2l + 2w 50 = 2(16) + 2w 50 = 32 + 2w 50 – 32 = 2w 18 = 2w w = 9 cm Therefore, the width of the rectangle is 9 cm.
Example 3: The perimeter of a rectangle is 60 cm and its width is 5 cm. Find its length.
Solution: Given, Perimeter = 60 cm and w = 5 cm Using the formula, Perimeter = 2l + 2w 60 = 2l + 2(5) 60 = 2l + 10 60 – 10 = 2l 50 = 2l l = 25 cm Therefore, the length of the rectangle is 25 cm.
In conclusion, the perimeter of a rectangle is the sum of the lengths of all its sides. We can calculate it using the formula Perimeter = 2l + 2w, where l is the length of the rectangle and w is its width. It is important to remember the formula and use it correctly to solve problems related to rectangles.