In this video we're looking at what congruent shapes are and we're going to run through a couple of examples. In maths the word congruent basically means identical in both shape and size. So congruent shapes are just those that have the same shape and size but something to watch out for is that they can be reflected or rotated which can make them look a bit different. To see this in practice, let's compare this main shape in the middle, which we'll label A, to these other five shapes, and see which of them are congruent.
Feel free to give the video a pause and have a go for yourself. So if you start with B, it's fairly easy to see that this one would be considered congruent, because it's exactly the same shape and size, and it's even the same orientation, which just means that it hasn't been rotated at all. If we look at shape C though, this one isn't congruent, because it's an entirely different shape.
Then looking at D, even though this is the same shape, it isn't the same size, so this one isn't congruent either. Now at first, shape E might look like it's a different shape, but it's actually just been reflected in this line here, so that it's a mirror image, and this means that it does count as being congruent with A. And finally our last shape F also looks a bit different at first, but that's just because it's been rotated 90 degrees counterclockwise.
It's still the same shape and size, so is congruent to A. As a practice, pause the video here and have a go at finding the two shapes out of these that are congruent to each other. So in this case the answer would be A and E.
because A is just a 90 degrees clockwise rotation of E, which is the same thing as saying that E is a 90 degrees counterclockwise rotation of A. Either way, these two have the same shape and size, so they're congruent. Anyway, that's everything for this video, it was only a quick one, so hope you found it useful, and we'll see you again soon.