There are infinitely many such shapes.
Polygon's parts of speech are poly- (many) and -gon (a suffix describing geometrical figures contained by line segments) Therefore a polygon just means many sided figure. They include but are not limited to: Squares Rectangles Triangles Pentagons Diamonds Rhombus' Septagons And all two dimensional figures rendered with straight lines
Each vertx has two adjacent angles.
Infinitely many. In fact, there are infinitely many circles, or infinitely many triangles.
there are two continents that are adjacent to the ring of fire.
Each of its 6 sides is adjacent - to four other sides.
How many significant figures are in the measurement 210 cm?
4 significant figures.
2 significant figures.