# Perimeter of a Triangle Formula

- Perimeter of a triangle is the total length of the sides of a triangle. The sides of the triangle may be equal or unique.
- If all the three sides are same, then it is known as an equilateral triangle.
- It is an isosceles triangle if two of the sides are equal.

- For a triangle to exist certain conditions need to be met:
**a + b > c****b + c > a****c + a > b**

Now, the formula for the** Perimeter of a Triangle **is given as,

\[\large Perimeter\;of\;a\;Triangle=a+b+c\]

Where,

a, b, c are the sides of the triangle.

### Solved Examples

**Question 1**: Find the perimeter of a triangle whose sides are of 6 cm, 8 cm and 6 cm?

**Solution**:

Given,

a = 6 cm

b = 8 cm

c = 6 cm

Perimeter of a Triangle = a + b + c

= 6 + 8 + 6

= 20 cm

**Question 2**: Find the perimeter of an equilateral triangle whose side is 6 cm?

**Solution**:

Being an equilateral triangle, all the sides are equal.

Thus, a = 6

Perimeter of an equilateral triangle= a + b + c = a + a + a = 3a

= 3 x a = 3 x 6

= 18 cm

**Question 3**: Find the perimeter of an isosceles triangle whose sides equal sides are 6 cm and the third side is 8 cm?

**Solution**:

Being an isosceles triangle, two sides are equal.

Thus, a = 6, b = 6 and c = 8

Perimeter of an isosceles triangle= a +b + c = a + a + c = 2a + b

= 2 x a + 8 = 2 x 6 + 8

= 20 cm

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