Given:
The perimeter of a triangle is 59 cm.
The first side is 7 cm shorter than the second side.
The third side is 4 cm less than twice the length of the first side.
To find:
The length of each side.
Solution:
Let x be the second side.
Then, according to the question,
First side = x-7
Third side = 2(x-7)-4
Perimeter of a triangle is the sum of all of its sides.



Add 25 on both sides.


Divide both sides by 4.

Now,
First sides =21 - 7=14 cm
Second side = 21 cm
Third side = 2(14)-4 = 24 cm
Therefore, the three sides of triangle are 14 cm, 21 cm and 24 cm respectively.