A triangle is normally nonconvex on a flat surface
A nonconvex polygon is a concave polygon. All polygons with 4 or more sides can be concave. An arrowhead is an example of a concave quadrilateral. The back of an envelop (where the sides are folded and glued together) is a concave pentagon.
A convex polygon.I suspect that what you mean is a convex polygon.
is this a polygon? is it concaver or convex
Any polygon that has an angle that is > 180º is a concave polygon. A convex polygon does not. e.g. All regular polygons are convex.
a polygon is convex
A convex polygon is one with no angle greater than 180 degrees. A non-convex polygon is one that is not without such an angle.
It is convex if you look at it from the inside but it is not any kind of polygon.
Yes, the angle sums will be the same regardless of whether or not it is a convex polygon.
Is a concave polygon.
A convex polygon.
A polygon is convex if you can take any two points inside the polygon and connect them with a line segment that is completely contained by the polygon. A non-convex polygon is one which contains at least two points such that the line joining them does not lie entirely inside the polygon.