Find the exterior angle

[Alphlax]

I'm given a set of interior angles and have to calculate the measure of exterior angles.
Q: The sum of interior angles of a regular polygon is given, Calculate the measure of each exterior angle.
1)2880 degrees
2)3780 degrees
3)4860 degrees

I have no idea how to do this please help!

 

[DrPhil]

I'm given a set of interior angles and have to calculate the measure of exterior angles.
Q: The sum of interior angles of a regular polygon is given, Calculate the measure of each exterior angle.
1)2880 degrees
2)2780 degrees
3)4860 degrees

I have no idea how to do this please help!

As the number of sides $\displaystyle n$ of a regular polygon increases, the sum of interior angles increases and the exterior angle (amount of bend between one side and the next) gets smaller:

n=3 (equilateral triangle), sum interior angles = 180°, exterior angle = 120°

n=4 (square) .............................................360°.........................90°

The sum of all exterior angles has to be 360°, in order to get back to the starting direction after walking all the way around the figure. Thus if you can find $\displaystyle n$, the answer to the question will be $\displaystyle 360°/n$. Use what you know about n=3 and n=4 to extrapolate.

If you need more help, show us what you have tried.

EDIT: one of the three numbers you typed in is wrong - please check.

 

[Alphlax]

I tried dividing it by 360 which just gave me "8" for the first one, I have the answer key and that says 20degrees so I know it's wrong.

Then I tried (2880-2)180/2880 to find the interior angle so I can subtract that from 360 but that gave me a decimal...

 

[pka]

I tried dividing it by 360 which just gave me "8" for the first one, I have the answer key and that says 20degrees so I know it's wrong. Then I tried (2880-2)180/2880 to find the interior angle so I can subtract that from 360 but that gave me a decimal...

You are seriously confused about the rules here.
Look at this page.

The formula $\displaystyle (n-2)\times 180^o=\text{ the internal angle sum}$ where $\displaystyle n$ is the number of edges.

Use that to find $\displaystyle n$ for $\displaystyle 2880^o$.

Then the external angle is $\displaystyle \left( {\frac{2}{n}} \right) \times {180^o}$