Perimeter is the sum of the lengths of the sides of any figure. Let’s find out the perimeter of a triangle, rectangle, square, and quadrilateral.
Perimeter of a Triangle
The perimeter of a triangle can be found by adding the length of its three sides. Let’s see some examples.
Example 1. Find out the perimeter of the triangle.
Solution.Length of side AB = 5 cm
Length of side BC = 7 cm
Length of side AC = 5 cm
The perimeter of the triangle = Length of AB + Length of BC + Length of AC
= 5 cm + 7 cm + 5 cm
= 17 cm
So, the perimeter of the triangle is 17 cm.
Example 2. Find out the perimeter of the triangle.
Solution.Length of side AB = 3 cm
Length of side BC = 4 cm
Length of side AC = 5 cm
The perimeter of the above triangle = Length of AB + Length of BC + Length of AC
= 3 cm + 4 cm + 5 cm
= 12 cm
So, the perimeter of the triangle is 12 cm.
Perimeter of a Rectangle
The perimeter of a rectangle is the sum of all four sides. We know that opposite sides of a rectangle are equal.
Perimeter of a rectangle = 2 x (Length + Breadth)
Example 1. Find out the perimeter of a rectangle whose length is equal to 5 cm and breadth is equal to 3 cm.
Solution.
Perimeter of the rectangle = 2 x (Length + Breadth)
= 2 x (5 cm + 3 cm)
= 2 x 8 cm
= 16 cm
So, the perimeter of the rectangle is equal to 16 cm.
Perimeter of a Square
The perimeter of a square is the sum of all four sides. We know all the sides of a square are equal.
Perimeter of a square = 4 x Side length
Example 1. The side of a square is 5 cm. Find the perimeter.
Solution.The perimeter of the square = 4 x Side length = 4 x 5 cm = 20 cm.
So, the perimeter of the square is equal to 20 cm.
Perimeter of a Quadrilateral
The perimeter of a quadrilateral is the sum of the length of all four sides.
The perimeter of the quadrilateral = Length of AB + Length of BC + Length of CD + Length of AD
Example 1. Find the perimeter of the quadrilateral.
Solution.Perimeter of the quadrilateral ABCD = 2 cm + 6 cm + 3 cm + 4 cm
= 15 cm
So, the perimeter of the quadrilateral ABCD is equal to 15 cm.
Now let’s find out the area of these shapes here.
AREA OF SHAPES
