### Theory:

Now, we shall find the perimeter of a rectangle.

Let us consider a rectangle $$ABCD$$ whose length is $$l$$ $$units$$ and breadth is $$b$$ $$units$$.

Then, the perimeter of the rectangle is given by:
Perimeter of the rectangle $$=$$ Sum of the measures of all four sides
Perimeter $$P =AB+BD+DC+CA$$ $$units$$

$$P=l+b+l+b$$ $$units$$

$$P= 2l+2b$$ $$units$$

$$P=2(l+b)$$ $$units$$

Thus, the perimeter of the rectangle is $$2(l+b)$$ $$units$$.
Example:
1. The length of the rectangle is $$5 \ cm$$, and breadth of the rectangle is $$3 \ cm$$. Find the perimeter of the rectangle.

Solution:

The length of the rectangle is $$l=5 \ cm$$.

The breadth of the rectangle is $$b=3 \ cm$$.

Perimeter of the rectangle $$=$$ Sum of the measures of all four sides

Perimeter, $$P=2(l+b)$$

Substituting the values in the formula, we have:

$$P=2\times(5+3)$$ $$cm$$

$$P=2\times(8)$$ $$cm$$

$$P=16 \ cm$$

Thus, the perimeter of the rectangle is $$16 \ cm$$.