please help.

the question is, How many degrees in a triangle which is 180 degrees, quadrilateral 360 degrees ??
is that right.
=]]

and i need help on the
11- gon ?
20- gon?
and it says what is the formula??

triangles - 180 degrees, yes

quadrilaterals - 360 degrees, yes

11-sided figure: http://www.mathonline.org/mho/view.cgi?27149

20-sided figure:
http://www.mathonline.org/mho/view.cgi?31282

The sum of the interior angles of a polygon is given by 180º(n-2) where n is the number of sides

Yes, you are correct! The sum of the angles in a triangle is always 180 degrees, while the sum of the angles in a quadrilateral is always 360 degrees.

Now, let's move on to polygons with more sides.

To find the sum of the interior angles of an n-gon (a polygon with n sides), you can use the formula:

Sum of interior angles = (n - 2) * 180 degrees

For example, for an 11-gon (a polygon with 11 sides), we can substitute n = 11 into the formula:

Sum of interior angles = (11 - 2) * 180 = 9 * 180 = 1620 degrees

So, the sum of the interior angles of an 11-gon is 1620 degrees.

Similarly, for a 20-gon, substitute n = 20 into the formula:

Sum of interior angles = (20 - 2) * 180 = 18 * 180 = 3240 degrees

Therefore, the sum of the interior angles of a 20-gon is 3240 degrees.

Remember, the formula for the sum of interior angles of an n-gon is (n - 2) * 180 degrees.