Polygons with equal area and perimeter but different number of sides? Let's say we have two polygons with different numbers of sides. They can be any sort of shape, but they have to have the same area, and perimeter. 
There could be such possibilities, but can someone show me with pictures? I just need visualize it.
Sometimes in life you just have to know it, and sometimes we need a picture shown in our faces :).

For any triangle there is a rectangle with the same area and perimeter. 
proof: by Heron's formula the area of the triangle with semiperimeter $S$ and triangle sides $a,b,c$ is $$\sqrt{S(S-a)(S-b)(S-c)}\leq \sqrt{\frac{8S^4}{27}}$$
A square with semiperimeter $S$ has area $\frac{S^2}{4}\geq\sqrt{\frac{8S^4}{27}}$.
We can then proceed to make the square into a rectangle, making the area smaller and smaller preserving the perimeter. Until the area is as small as the triangle's.
