<p>What's the rule of polygons ?
for example: if the given are the number of angles and that they are equal
how can i know the measure of each angle?</p>
<p>(n-2) x 180
__________ = Measure of each angle in a regular (all angles equal) polygon.</p>
<pre><code> n
</code></pre>
<p>(n-2) x 180 = Sum of measures for any polygon (given the number of angles).</p>
<p>Example: What are the sum of measures of a quadrilateral (4-sides)? (4-2) x 180 = 360. OK, how about the measure of each angle in a regular quadrilateral? (4-2 x 180) / 4 = 360 / 4 = 90, or what we know as the square.</p>
<p>For more information, go to <a href=“http://www.khanacademy.com%5B/url%5D”>www.khanacademy.com</a></p>
<p>Oh, and by the way, I’m from Alexandria, Egypt, too. Which school are you in?</p>
<p>(n-2) * 180/ n</p>
<p>n= The number of sides</p>
<p>For example, to find the measure of each angle in a hexagon, all you do is (6-2)*180/ 6 = 120.</p>
<p>Oh… ty 
Really? AAST… wbu ?</p>
<p>Thank u so much for helping :)</p>
<p>Another way, kind of sneaky but quick: start by finding the exterior angles first! Since the total of exterior angles is 360 for any convex polygon, just divide 360 by the number of sides. That gives you the exterior angle. Then subtract from 180 to get the interior angle. (I know you get the same answer, but for some reason, I’ve always liked this way…)</p>
<p>Thanks pckeller</p>
<p>Here is a quick geometric way to figure this out. Draw the polygon, and then split the polygon into quadrilaterals and triangles, by drawing line segments between vertices of the polygon. Then just remember that a triangle has 180 degrees, and a quadrilateral has 360 degrees. Sum up the total number of degrees in these triangles and quadrilaterals.</p>
<p>For example an octogon (8 sided polygon) can quickly be split up into 3 quadrilaterals. So there are 3*360 = 1080 degrees in an octogon. If the octogon happens to be regular (all sides and angles equal), then each angle has 1080/8=135 degrees.</p>