point - a geometric point in space   

line - a geometric figure that goes on for ever on both sides.  It is named with two letters with a line symbol above them.

segment - a line that has two end points at the end that stops it from going on forever.  It is named with two letters with a line segment symbol above them.

Ray - a point that starts at one end and goes on forever in the opposite direction.  It is named with two letters, always with the endpoint first, with a ray symbol above them.

angle - two rays or line segments that share the same vertex.  We name an angle with three letters in order along the angle or by the vertex. 

Click here to see an example - http://www.yourteacher.com/prealgebra/namingangles.php

acute angle - an angle that is more than 0 degrees and less than 90 degrees.  It is the smallest angle.   

right angle - is the only angle with a square corner and is exactly 90 degrees.

obtuse angle - an angle that is more than 90 degrees and less than 180 degrees.

straight angle - an angle that measures exactly 180 degrees and can be a line.

relfex angle - any angle that is larger than 180 degrees and less than 360 degrees.  The arc of the circle measures around the outside of the angle.  If it does not have the outside arc, it should be an acute, right, or obtuse angle. 

quadrangle (quartilateral) - a shape with four sides and four angles.  If we name it with letters, the name must follow around the shape in order.

kite -has four straight sides, two short and two long, where the two short sides touch each other and the two long sides touch each other.  A kite has four angles, but is not a parallelogram.

rhombus - a square with two opposite corners (veticies) pulled out.  It can be a square, parallelogram, quadrangle, and polygon.  It has two pair of parallel sides and all the sides are the same length.

polygon - a shape with no curved sides (they all have to be straight), all sides must connect to create one interior, and there may not be any intersecting sides.

regular polygon - a polygon with all sides the same length

concave - any polygon that caves in in at least one spot. 

convex - a polygon that does not cave in.

congruent - geometric figures that have the same shape and size are considered congruent.