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