How can you add a figure to a composite figure without increasing its perimeter? draw a diagram to support your answer

We know perimeter is the amount of units around a figure. If we want to add to a composite figure without increasing the perimeter, we must add to it by using the space on the inside of the figure. For example, if we have a square, we can make it a composite figure by splitting the square with a diagonal line. This adds to the figure without adding to its perimeter.   

Wow. that is a really cool question.