2.
a triangle with all sides equal and all angles equal
3.
the intersection point of two sides of a plane figure
4.
a triangle with one internal angle equal to 90 degrees
5.
a rectangle having all four sides of equal length
6.
an angle less than 90 degrees but greater than 0 degrees
8.
a polygon with four sides
9.
an angle greater than 90 degrees but less than 180 degrees
10.
a quadrilateral plane figure having two parallel and two nonparallel sides
