How do you figure out the angle measures of an irregular concave polygon?

Answer 1

Well, each angle has whatever value it happens to have. The only limitation is that the values can't be negative or greater than 360 degrees, and the total for all of the angles must be the appropriate value for a polygon with that number of sides (180 degrees for a triangle, 360 for a quadrilateral, 540 for a pentagon, etc. ... in general, 180 (n-2), where n is the number of sides).

Because you say it is a concave polygon, you are indicating that at least one angle exceeds 180 degrees. Obviously, this can't be a triangle (since the sum of ALL the angles of a triangle equals 180 degrees). But it can be any other polygon. The fact that one angle exceeds 180 degrees does not change the criteria given above (each angle greater than 0 and less than 360, and the sum of the angles being appropriate for the number of sides of the polygon).