Find the sum of the interior angle of:pentagon,15-gon,and 18-gon.© BrainMass Inc. brainmass.com December 24, 2021, 4:41 pm ad1c9bdddf
In general the sum of the interior angle of a closed shape with m sides (a "m-gon") is equal to 180*(m-2). Because by drawing lines from a corner to all the non-adjacent corners we can draw exactly (m-2) triangles inside the "m-gon", such that the total sum of the sum of interior angles of all triangles will ...
This shows how to find the sum of interior angles of various polygons. The interior angles of pentagons are examined.