A **perimeter** is a path that surrounds an area. The word comes from the Greek *peri* *represent * (around) and meter (measure). The term may be used either for
the length or its path - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference.

What is semi perimeter?

Semi perimeter is given by half of the perimeter value.

- Take any geometrical shape first we will find the perimeter of that shape
- Semi perimeter = perimeter /2

**Example: 1**

What is the semi perimeter of the square with the each side measuring 5 feet.

**Solution:**

First we will find the perimeter of square

We know that formula for perimeter of square =4a

Calculate the perimeter =4*5 feet

=20 feet

Now we find the semi perimeter

Semi perimeter = 20/2

=10

Therefore semi perimeter of the given square is 10 feet

**Example: 2**

What is the semi perimeter of following rectangle length is 9 feet and width is 7 feet.

**Solution:**

First we will find the perimeter of the rectangle

We know that formula for finding the perimeter of rectangle is =2(l+w)

Substitute the length and width in the formula we get

=2(9+7)

=2(16)

=32 feet

Now we calculate the semi perimeter

Semi perimeter =32/2

=16 feet

**Therefore the semi perimeter of given rectangle is 16 feet.**

**Example: 3**

Calculate the semi perimeter of following triangle side of the triangle is 12 ,15 ,11

**Solution:**

First we will find the perimeter of triangle

Already we know that formula for find the perimeter of triangle is P= a+b+c

Substitute the sides’ value into the formula

P=12+15+11

P=38

Now we will find the semi perimeter

Semi perimeter =38/2

=19

**Therefore the semi perimeter of given triangle is 19**