Concave polygon Concave polygon A simple polygon that is not convex is called concave, non-convex or reentrant. A concave polygon will always have at least one reflex interior angle—that is, an angle with a measure that is between 180 degrees and 360 degrees exclusive. Some lines containing interior points of a concave polygon intersect its boundary at more than two points. Some diagonals of a concave polygon lie partly or wholly outside the polygon. Some sidelines of a concave polygon fail to divide the plane into two half-planes one of which entirely contains the polygon. None of these three statements holds for
38 Degrees multi-issue movement. It aims to empower UK citizens by providing easy ways for them to take action on the issues they care about, e.g., climate change, human rights and poverty. It claims "it’s 38 Degrees members who set priorities and we decide on what we campaign on together". They publish the results of their membership polls on their website. While 38 Degrees refers to 'members', there is no formal membership and these are simply people on its email mailing list. Each week 50,000 members, chosen at random, are asked to vote for their top priorities; only ones where there is