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## 4th grade

### Course: 4th grade > Unit 11

Lesson 6: Line of symmetry# Symmetry review

CCSS.Math:

Review symmetrical shapes and lines of symmetry. Then, try some practice problems.

## Line of symmetry

A start color #1fab54, start text, l, i, n, e, space, o, f, space, s, y, m, m, e, t, r, y, end text, end color #1fab54 is a line where we can fold the image and have both halves match exactly.

**Example:**

When we divide the figure with Line start color #1fab54, A, end color #1fab54, the resulting two parts are mirror images of each other:

Line start color #1fab54, A, end color #1fab54 is a line of symmetry.

*Want to learn more about lines of symmetry? Check out this video.*

## Symmetrical figures

Shapes are start color #aa87ff, start text, s, y, m, m, e, t, r, i, c, a, l, end text, end color #aa87ff if they have at least one start color #1fab54, start text, l, i, n, e, space, o, f, space, s, y, m, m, e, t, r, y, end text, end color #1fab54 on them.

**Example:**

This shape is start color #aa87ff, start text, s, y, m, m, e, t, r, i, c, a, l, end text, end color #aa87ff:

Because we can draw at least one start color #1fab54, start text, l, i, n, e, space, o, f, space, s, y, m, m, e, t, r, y, end text, end color #1fab54 on it:

*Want to learn more about symmetrical figures? Check out this video.*

## Practice

*Want to try more problems like this? Check out these exercises:*

Identify lines of symmetry and symmetrical figures

Draw lines of symmetry and symmetrical figures

## Want to join the conversation?

- How many lines of symmetry does a circle have(43 votes)
- Circles have an infinite amount of lines of symmetry. You can go on and on and on and never find a specific number of lines of symmetry. Circles are the only figures that have an infinite amount of lines of symmetry.(91 votes)

- how many lines of symmetry does a circle have(15 votes)
- A circle has infinite lines of symmetry(16 votes)

- how to find total number of lines of symmetry(9 votes)
- just do it as many times and many ways till you get all you need(13 votes)

- I did not understand how the pentagon had symmetry that way can you help me please?(8 votes)
- Yes, if you fold the pentagon over the dotted line, then the two pieces would match perfectly.(6 votes)

- so the amount of sides there is in the shape is how much lines of symmetry there is in that shape(5 votes)
- Symmetry is basically two sides of a shape that are the same. Imagine a triangle split in half. That would be symmetrical. Good luck and keep practicing!(12 votes)

- How many line of symmetry does a circle have?(7 votes)
- A circle has infinite amount of lines maybe 20 or more(5 votes)

- how do you solve decomposing angles when there is no sign of solving it. it is impossible when you have to subtract the numbers and then the answer is wrong, i never get the decomposing angle questions right, i always get 0% in them. geometry is difficult. isn't it. i always try to solve the questions if they are not right, but it never is right and i never get them right even after having a second go at them.(5 votes)
- Every body can make mistakes just keep trying(7 votes)

- whats the meaning of life(6 votes)
- that one was hard and is there going to be more of that because that was hard and fun.・ω・(5 votes)
- How much lines does a star have(3 votes)
- Draw out a star and count them. For your normal 5-pointed star, you can draw a line of symmetry straight down the middle. You can also rotate the star so that the next point is on top, and draw a vertical line of symmetry for that. Keep going, and you end up with 5 lines of symmetry, one for each point.(4 votes)