 Triangles. We learn about these a lot in maths. They're the simplest polygons. They have three sides and three angles. We can split all other polygons down into triangles, like this pentagon. Even a complicated irregular polygon, like this. There are many different topics in which triangles will pop up, so it's quite important that we know about the different types, which is what we're going to look at in this video. What do you notice about the sides and the angles in these different types of triangles? Pause the video and have a think. Is this what you discovered? Did you realise that a right-angled triangle can actually be an isosceles triangle, if it has two equal sides and angles? Or it can be a scalene, if everything is different. The only tricky part to this is remembering the different names. Equal actual is easy. It sounds like equal. All sides and angles are equal. Isosceles and scalene are a little harder to remember. A good bit of general knowledge is that the prefix iso means equal. So in chemistry, you learn about isotopes, which are atoms that have an equal number of protons. Isometric paper is made up of lots of equal triangles. An isosceles triangle is one that has equal legs, two legs of the same length, and then the base. So just remember that the word isosceles means equal legs. And so isosceles triangles have two sides and two angles the same because we have two legs. So then all you need to remember is that in scalene triangles, everything is different. Here's a question for you to do to test your triangle knowledge. Pause the video, work it out and click play when you're ready. Did you spot that this right angle triangle here is also an isosceles triangle? And this one is also a scalene triangle. Two last questions for you to answer. What do the three angles in any triangle add up to? And what is the size of one angle in an equilateral triangle? If you didn't already know, the three angles always add up to 180 degrees. And because an equilateral triangle has three equal angles, each angle must also always be 60 degrees. So there we have our different types of triangles. Just find a way that works for you to remember the different names. As I said earlier, I always remembered isosceles means equal legs. If you liked the video, give it a thumbs up and don't forget to subscribe. Comment below if you have any questions. Why not check out our Fuse School app as well? Until next time.