Poiygons. What are they? It sounds like some type of Pokémon, but actually all it means is a shape with straight sides. These sides can be any length - if they are different lengths we call them 'irregular' polygons. If the sides are all the same length, they're regular polygons.
Have a watch of this BBC clip on polygons to explain further;
You probably know a few polygons already. These are all regular versions, since the sides are the same, and they're named after how many sides they have (usually from the Latin of Greek for that number), e.g. tri- means 3, quad- means 4, pent- means 5 and so on.
Log onto Mathletics and see if you can Collect the Polygons!