Geometry: rational symmetry

[rachelmaddie]

The star exhibits rotational symmetry. What is the magnitude of the symmetry of the star?

72 degrees
60 degrees
90 degrees
120 degrees

I need this explained

 

[Harry_the_cat]

Imagine cutting the star out of cardboard, placing it on a piece of paper and tracing around it. Put a pin in the middle. How many degrees would you have to rotate it through so that it again lies on top of your tracing lines?

 

[rachelmaddie]

Imagine cutting the star out of cardboard, placing it on a piece of paper and tracing around it. Put a pin in the middle. How many degrees would you have to rotate it through so that it again lies on top of your tracing lines?

60 degrees

 

[Harry_the_cat]

How did you get that?

 

[rachelmaddie]

How did you get that?

I do not understand how to find the magnitude

 

[rachelmaddie]

I do not understand how to find the magnitude

So, 360/5 = 72 degrees

 

[Harry_the_cat]

Yes well done!