acute  angle with a measure less than 90 degrees
angle   two rays with a common endpoint called the vertex
area  number of square units needed to cover a given space
complementary  two angles whose measures have a sum of 90 degrees
congruent  equal
degree  a unit for measuring angles
geometry   branch of mathematics that deals with the measurement, properties, and relationships of points, lines, angles, surfaces and solids
intersecting  lines that cross at one point
isosceles  triangle with two congruent sides
length  longer or longest dimentsion of an object
obtuse   angle that measures more than 90 degrees but less than 180 degrees
parallellines  lines in the same place that never intersects
parallelogram  quadrilateral with opposite sides parallel and each pair of opposite sides and angles are congruent
perimeter  distance around a polygon
plane  flat surface extending in all directions
point  exact location in space
polygon  closed plane figure made up of line segments
puzzle  solve with difficulty or ingenuity
quadrilateral  polygon with four sides and four angles whose sum is 360 degrees
ray  part of a line that has one endpoint and extends in one direction without end
rectangle  parallelogram with four right angles
rightangle  angle that measures 90 degrees
rotation  transformation obtained by rotating a figure a given turn angle about a point
shapes  give a particular form or shape to
similarity  quality or state of being similar
square  four equal sides and four right angles
supplementary  two angles whose measures have a sum of 180 degrees
symmetry  correspondence in size, shape, and relative position of parts on opposite sides of a dividing line
tangram  Chinese puzzle made by cutting a square of thin material into seven pieces which can be recombined into many different figures
triangle  polygon having three sides
vertex  point where two mor more rays meet
width  a distance from side to side