An edge.
is called an edge.
A line is.
line
A Circle.
The intersection of two lines is a point. If both lines are straight the figure of four separate triangles are formed. The type of triangles are dependent on the angle of the intersection.
Three dimensional space.
A dihedral angle.
square
a square
An edge.
A parabola is the figure formed by the intersection of a circular cone and a plane that lies parallel to the edge of the cone. (the cone does not have to be a right [90°] circular cone).
A cylinder.