 What do these shapes all have in common? They're all two dimensional shapes with four sides and four angles. These are known as quadrilaterals. Quad means four, laterals means sides. In this video we're going to look at the properties of quadrilaterals in more detail. So they all have four sides, they all have four angles, they all have four vertices or corners. What about the sum of the interior angles? The interior angles always add up to 360 degrees. We're going to have a look at these six quadrilaterals in more detail. Before we start, did you know that squares, rectangles and rhombuses are all types of parallelograms? So let's start at the top with the one you probably already know all about. Squares. Four equal sides, four right angles and opposite sides are parallel. What about rectangles? Also four right angles and opposite sides are parallel. But this time the lengths aren't all the same. Opposite sides are equal in length. These and these. Did you know that a square is a type of rectangle? What about a rhombus? What do you notice about its sides and angles? Pause the video and have a think. Four equal sides, opposite sides are parallel and equal in length. Opposite angles are equal. I always think of a rhombus as a tipped over square. Did you know that a square is a type of rhombus? So now parallelograms. Just like a rhombus is a tipped over square, a parallelogram is a tipped over rectangle. I told you earlier that squares, rectangles and rhombuses are all types of parallelograms. So what does it mean to be a parallelogram? Pause the video and have a think. They have parallel opposite sides that are equal in length, so these and these. The opposite angles are also equal, like in rhombuses. Squares, rectangles and rhombuses all meet these requirements, hence their parallelograms. In England we call them trapezians. In America they're trapezoids. They simply have one pair of parallel sides. As trapeziums have such a simple definition, it actually means that squares, rectangles, rhombuses, parallelograms are also all trapeziums. Last up we have kites. What do you notice about a final type of quadrilaterals? Pause the video and have a think. They have two pairs of sides that are equal in length, they always have one pair of equal angles, and they're not so important but worth mentioning, the diagonals cross at 90 degrees. So quadrilaterals are actually all very interconnected. By definition a square is a quadrilateral, a trapezium, a parallelogram, a rectangle and a rhombus. Time to test your knowledge. Pause the video, answer these questions and click play when you're ready. How did you get on? So that's the end of quadrilaterals. Just remember that they're all very interconnected and so have similar properties. 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 Fusical app as well. Until next time.