To work this out, you find out how many triangles can fit into the shape.
To do this, you take the number of sides and subtract it by 2.
So in a polygon with 11 sides, there are:
9 triangles (<em>11 - 2 = 9)</em>
Remember, the total number of angles in one triangle is <u>180 </u>degrees.
So to work out the total number of angles in a polygon, you multiply the <u>number of triangles</u> in it by <u>180</u>.
So the total sum of interior angles in a polygon with 11 sides is:
180 x 9 = 1620 degrees <em>(180 degrees times number of triangles)</em>
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Answer:
1620 degrees
