What is the sum of a pentagon's angles?

the sum of a pentagons angle is 360 degrees

I assume you want the sum of the vertex angles of a regular pentagon.

The measure of one of the vertex angles is given by (n-2)*(180)/n where n is the number of sides of the pentagon.

So we have (5-2)*(180)/5 = 3(36) = 108º

And since we have 5 of these, then 5(108º) = 540º

And that's it !!!

I draw this for a different question recently.  It is relevant to you.

http://gyazo.com/152d627a05e4fe0cf19dd64f358e6570