The sum of all the interior angles is 1800 degrees. In any polygon the exterior angles all add up to 360 degrees. So it is 1800.
B. 150 degrees,
The interior angles are 150 degrees. The exterior angles are 30 degrees, Hence 30•12=360, 150•12=1800.
C. No, not without the use of other regular polygons to fill the gaps in between. So, you can use it to tile a flat surface, but there will be gaps and voids to fill with other tile. Or if you want to get technical, for you tile the plane by congruent regular polygons, there must be polygons meeting at each vertex. Thus the interior angles of each polygon must be 2/, for some positive integer . The vertices always come together at some point. That is, with rectangular tiles there are always groups of 4 tiles, and the 4 corners are 90 degrees each so 4 of them add up to 360. A hexagon has an interior angle measure of 120, and 120 is the greatest factor of 360 (other than 180, which is a straight line, or 360). If you have polygons with 7 or more sides, their corners will not fit nicely to add up to 360 degrees:)
