Perimeter

1. Define variables:

Let be the breadth of the rectangle (in cm).

The length, , is given as five times the breadth: .

2. Perimeter formula:

The perimeter, , of a rectangle is given by:

3. Substitute and simplify:

Substitute into the perimeter formula:

4. Apply the minimum perimeter condition:

The minimum perimeter is given as 180 cm, so .

Therefore,

5. Solve for the breadth:

Divide both sides of the inequality by 12:

6. Interpret the result:

The breadth, , must be greater than or equal to 15 cm.

Correct Answer: (B) Breadth 15 cm