 Do you know what the word polygon means? It comes from Greek. Poly means many, gon means angles, many angles. Polygons are two-dimensional shapes that are made up of straight lines with all the sides joined up. They can be regular with equal angles and equal sides or irregular. They can even intersect themselves. It's important to understand shapes and angles for many different professions. Engineers, architects, artists, farmers, construction, gardeners, which is why we study them in maths. Depending upon how many sides they have, different polygons have different names. Starting with three sides, I'm pretty sure you already know these are called triangles. There may be different types but they all have three sides and three angles. Next come quadrilaterals. Four sides, four angles. Now for five, six, seven, eight, nine and ten sided shapes. Pentagon, hexagon, heptagon, octagon, nonagon and decagon. These can be quite tricky to remember so try and connect them with something. Quad for quad bikes which have four wheels. The pentagon building in America which has five sides or P-E-N-T-A on your fingers is five. Hex has an X as does six. Octopus have eight legs. N for nonagon and for nine. Deck is for ten just like our decimal system is base ten. Find a way that works for you to help you remember these names. So here are some quick questions to quiz your polygon knowledge. Pause the video, answer the questions and click play when you're ready. Did you get them all correct? We need to know the names and number of sides of different polygons so that we can calculate the interior and exterior angles of them which we'll look at in another video. Please like and share our videos with your friends and if you've got any questions just ask below.