Question 18501
For a polygon with n sides,
<font color=blue>exterior angle=360/n</font>
so for a 30-side polygon,
ext angle=360/30=12 degrees
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Now,
<font color=blue>interior angle=180-exterior angle</font>
So for 30-sided polygon,
int angle=180-12=168 degrees
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Sum of int angles of a polygon=
<font color=blue>{{{(n*(180-(360/n)))}}}</font>
=n*int angle
=30*168
=5040 degrees
<P>
Hope this helps,
Prabhat