The perimeter of triangle ABC is 16 cm, AB is 3 cm less than the side of AC. Find the length of the side BC if AC = 7 cm.

To solve this geometric problem correctly, you need to know the formula for the perimeter of a rectangle.
But first, in order to understand what actions need to be performed, we need to draw up a short condition for this task:
R ABC – 16 centimeters;
AB -? centimeters, 3 centimeters less than the speaker;
AC – 7 centimeters;
BC -? centimeters;
First, we find the length of the side AB:
7 – 3 = 4 centimeters;
Now we find the length of the side BC using the perimeter formula:
16 – 4 – 7 = 5 centimeters – BC;
Answer: 5 centimeters.