Polygon Names in English From 3 to 20 Sides

Do you know the English name for a shape with nine sides? In this short video, you will learn the names of polygons in English, from the simple triangle to decagon, with clear pronunciation for each word. We start with the shapes everyone knows: triangle, square and rectangle. Then we move to pentagon, with five sides, hexagon, with six, heptagon, with seven, octagon, with eight, nonagon, with nine, and decagon, with ten. Most of these names come from Greek numbers, so once you notice the pattern, like penta for five and hexa for six, they become much easier to remember. This vocabulary is useful for math classes, exams, school projects and helping children with homework in English. Watch the video, pause after each shape and repeat the word out loud. Practice a few names each day and soon you will be able to name any polygon confidently.