5. The perimeter of a triangle, where side $b$ is $1 \mathrm{~cm}$ longer than side $a$, and side $c$ is $1 \mathrm{~cm}$ longer than side $b$, is $156 \mathrm{~cm}$. What is the perimeter of a square whose side length is equal to the length of side $b$ of the given triangle?
5. Side $a$ is $1 \mathrm{~cm}$ shorter than side $b(a=b-1)$, and side $c$ is $1 \mathrm{~cm}$ longer than side $b(c=b+1)$.

The sum of the lengths of all three sides is then $3 b$

4 points

Since the perimeter of the triangle is $156 \mathrm{~cm}$, we get that $b=52 \mathrm{~cm}$. 3 points

The perimeter of the desired square is $4 \cdot 52=208 \mathrm{~cm}$.

3 points