The perimeter of triangle ABC is 62cm, BC = 17cm, AB = CA. Find the length of side AB.

We are faced with a simple geometric problem.
Let’s make a short condition to better understand the wording:
The figure is a triangle;
Perimeter – 62 cm;
BC – 17 cm;
AB = AC -? cm;
Since AB = AC, the triangle that we are considering in the problem is isosceles.
So, you need to remember what a perimeter is:
The perimeter is the sum of the lengths of all sides;
Thus, the perimeter of the proposed triangle will be equal to:
P = BC + AB + AC;
62 = 17 + AB + AC;
Let’s denote AB and AC for x:
2x = 62 – 17;
2x = 45;
x = 22.5 cm – AB and AC;
Answer: 22.5 cm.