 Parallel lines are always the same distance apart and they never meet. We use arrow hairs to show that lines are parallel. See how these lines have one arrow. Then, because these ones are also parallel, but not parallel to the ones before, they have two arrows. Parallel lines create lots of angles that are either the same or correspond to one another. In this video, we're going to discover what these key words mean and we're going to use them to find missing angles. Before we start, you should already know that there are 180 degrees in a straight line. That's a key piece of knowledge that we use when solving parallel line angle questions. So what do you notice about alternate angles? Alternate angles are always the same. They make a Z. So you can look out for Zs, but you do also need to remember the name, Alternate. These angles are called corresponding angles. What do you notice about them? Corresponding angles are also the same. But this time, they look more like an F. These are called interior angles or co-interior angles. What do you notice about them? Interior angles always add up to 180 degrees. These look like a C rather than an F and a Z. And so the final thing we need to know are vertically opposite angles. What do you notice? Opposite angles on a point are always equal. Using these four angle facts that there are 180 degrees on a straight line, 360 degrees around a point and 180 degrees in a triangle, here are some questions to do. Pause the video, find the angles and click play when you're ready. Did you get the angles right? Your explanations may be different, so just make sure you used the correct terminology. Here are my reasons. As long as you use the correct terminology than any correct reason counts, here's a final puzzle for you to do. With just these four angles, can you find all of the other internal angles? Pause the video and then click play when you want the answers. 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.