SOLUTION: What type of shape is this in the link? http://1.bp.blogspot.com/-xgH3jxjnQyw/ThAlrtxcZnI/AAAAAAAAAAg/uzLAnVQ8RrM/s320/IMG_20110703_011556.jpg Choices: A. regular concave

Algebra ->  Equations -> SOLUTION: What type of shape is this in the link? http://1.bp.blogspot.com/-xgH3jxjnQyw/ThAlrtxcZnI/AAAAAAAAAAg/uzLAnVQ8RrM/s320/IMG_20110703_011556.jpg Choices: A. regular concave       Log On


   



Question 466766: What type of shape is this in the link?
http://1.bp.blogspot.com/-xgH3jxjnQyw/ThAlrtxcZnI/AAAAAAAAAAg/uzLAnVQ8RrM/s320/IMG_20110703_011556.jpg
Choices:
A. regular concave polygon
B. convex polygon
C. concave polygon
D. not a polygon
E. regular convex polygon
Thank you

Found 2 solutions by ccs2011, Theo:
Answer by ccs2011(207) About Me  (Show Source):
You can put this solution on YOUR website!
The figure is closed with more than 2 sides so it is a polygon
Not all sides are equal length, so it is not a regular polygon
Convex means pointing outward, concave means pointing inward
Notice the lines go back in on itself, thus concave.
Answer: Concave Polygon

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
here's a good reference that will help you understand convex and concave polygons.
http://www.mathopenref.com/polygonconvex.html
the convex polygon will not have an internal angle greater than 180 degrees.
the concave polygon will.
the figure shown in your jpg file looks very much like a concave polygon.
there is no such a thing as a regular concave polygon (see the reference).
your figure looks very much like a concave polygon.
from wikipedia:
A simple polygon that is not convex is called concave[2] or reentrant.[3] A concave polygon will always have an interior angle with a measure that is greater than 180 degrees.
It is always possible to cut a concave polygon into a set of convex polygons. A polynomial-time algorithm for finding a decomposition into as few convex polygons as possible is described by Chazelle & Dobkin (1985).[4]
end of from wikipedia: