Perimeter is a path having a two-dimensional shape and is the length of the boundary. In greek peri means 'around' and meter is 'measure'. It is the distance around a closed plane figure.

Perimeter is found by adding length of all the three sides.Given below are the simple steps which can be used to find the perimeter of a triangle.
  • Remember the formula which is, P = A + B + C
  • Find the value for all the three sides.
  • The final step is to add all the three sides and to remember to put the units for the given problem.

Solved Examples

Question 1: Find the perimeter of the triangle having 12 cm, 22 cm and 25 cm.
Solution:
 
Let A = 12 cm, B = 22 cm, C = 25 cm.
The formula to find the perimeter of a triangle is
P = A + B + C
Plugging the given values we get
P = 12 + 22 + 25
P = 59 cm.
Therefore the perimeter of a triangle is P = 59 cm.
 

Question 2: Find the value of A if P = 29, b = 6 and c = 14
Solution:
 
Here for the given problem we need to find the value of 'A'.

As we know, the formula to find the perimeter is P = A + B + C
Plug in the know values to find the value of A.
29 = A + 6 + 14
29 = A + 20
A = 9

Therefore the value of 'A' for the given problem is 9.