In an isosceles triangle, one of the sides is 12 cm, and the perimeter is 35. find all the sides.

It is known:

Isosceles triangle;
One side is 12;
The perimeter is 35.
Solution:

In an isosceles triangle, 2 sides are equal. Since one side is known and equal to 12, then the second side equal to it is also equal to 12.

In order to find the perimeter, you need to fold all the sides. We get the formula:

P = a + b + c;

35 = 12 + 12 + c;

35 = 24 + c;

We leave the unknown values on one side, and transfer the known values to one side. Then we get:

c = 35 – 24;

c = 11;

Answer: The sides are 12, 12 and 11.