In this lesson, we will learn about line symmetry and what is line of symmetry.
About This Lesson
Looking at the picture on the right, we can see that the two sides of the picture are identical. Knowing this, we can say that this picture is symmetrical.
Now, we will learn about
and what is
line of symmetry
You can proceed by reading the
first or watch the
or try out the
When we draw line across this equilateral triangle as shown in the picture, we can see that both sides of the triangle are the identical.
With this, this triangle is symmetrical along this line and this line is called
line of symmetry
below will show you more on this visually.
Next, when we observe carefully, this equilateral triangle in fact has
3 lines of symmetry
So next time, when you are given a shape to find all the lines of symmetry, be reminded to carefully analyze the shape carefully to avoid missing out any of these lines.
Now, watch the following math video to learn more.
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Math Video Transcript
00:00:02.210 This is a lesson on line symmetry. 00:00:07.010 Let's take a look at this picture. 00:00:09.240 Now, when we draw a line across this picture, we will divide this picture into 2 sides. 00:00:16.230 Let's see what happens when we fold this picture along this line. 00:00:21.150 When folded, we can see that both sides of the picture are exactly the same. 00:00:27.040 When this happens, this picture is said to be symmetrical, and this line can be called the line of symmetry. 00:00:34.040 Next, let's try to fold this picture along this line. 00:00:38.200 Notice that, when we fold, both sides of the picture are not the same. Therefore, this line is not the line of symmetry. 00:00:48.190 Let's try to fold along this line now. Again, both sides are not the same. Therefore, this line is not the line of symmetry. 00:01:00.110 Next, let's try to fold along this line. Again, both sides are not the same. Therefore, this line is not the line of symmetry. 00:01:13.240 With all these observations, we can see that this picture has only 1 line of symmetry. 00:01:21.160 Next, let's examine the line symmetry for this star. 00:01:26.050 Notice what happens, when we fold this star along this line. 00:01:30.220 When folded, we can see that side sides of the star, are exactly the same. 00:01:36.210 Hence, we can say that this star is symmetrical along this line. 00:01:42.240 How about this line? We can see that, this star is not symmetrical along this line. 00:01:51.100 Next, as for this line, we can see that, this star is symmetrical along this line. 00:01:59.000 Next, as for this line, we can see that, this star is not symmetrical along this line. 00:02:06.180 With some observations, we will notice that this star, has a total of 10 lines of symmetry. 00:02:14.240 Next, let's examine the line of symmetry for this ring. 00:02:19.190 When I fold this ring, we can see that this right is symmetrical along this line 00:02:25.110 The ring is also symmetrical, when it is folded along this line. 00:02:30.200 The observation is the same of this line. 00:02:36.000 Now, if we observe carefully, we will realize that this ring has infinite number of lines of symmetry. 00:02:43.040 Here, you can only see a few lines of symmetry, because I can not draw infinite number of them. 00:02:50.020 That is all for this lesson. Try out the practice question to further your understanding.
Practice Questions & More
Multiple Choice Questions (MCQ)
Now, let's try some MCQ questions to understand this lesson better.
You can start by going through the series of
questions on line symmetry
or pick your choice of question below.
on finding the lines of symmetry of a five-pointed star
on line symmetry of a parallelogram
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