###
acute angle

an angle with measure greater than 0 degrees and less than 90 degrees

###
acute triangle

a triangle in which all three angle measures are less than 90 degrees

###
area

the measure in square units of the interior region of a plane figure or the surface of a three dimensional figure

###
area of triangle

base times height and divide by two

###
base

a special side of a polygon used to compute area

###
composite figure

a shape made of several simpler figures

###
diagonal

a segment that joins two vertices of a polygon and is not one of the sides

###
division

inverse of multiplication

###
equilateral triangle

triangle with all three sides the same length

###
height

the perpendicular distance between two bases, or a vertex and a base

###
hexagon

a polygon with 6 sides

###
isosceles triangle

a triangle with at least two sides equal in length

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line segment

a part of a line with endpoints

###
obtuse angle

an angle greater than 90 degrees and less than 180 degrees

###
octagon

a polygon with eight sides

###
parallel

two lines which never intersect and are the same distance apart

###
parallelogram

a quadrilateral with opposite sides parallel

###
pentagon

a polygon with five sides

###
perpendicular

lines, segments or rays that intersect to form right angles

###
polygon

a two dimensional closed figure with straight line segments connected end to end

###
quadrilateral

a polygon with four sides

###
ray

a portion of a line that has one endpoint and extends forever in one direction

###
rectangle

a quadrilateral with four right angles

###
regular polygon

a polygon with all sides congruent and all angles having the same measure

###
rhombus

a quadrilateral with four congruent sides

###
right angle

an angle with a measure of 90 degrees

###
right triangle

a triangle with one right angle in it

###
scalene triangle

a triangle with no two sides of equal length

###
square

a quadrilateral with four congruent sides and four rigth angles

###
square measure

units used to describe the measure of an area in the form of 1 * 1 unit squares

###
subproblems

a problem solving strategy which breaks problems into smaller parts which must be solved in order to solve the original problem

###
trapezoid

quadrilateral with exactly one pair of parallel sides

###
triangle

a polygon with three sides

###
vertex

the point at which two rays, line segments or lines meet.

###
vertical angles

angles opposite each other when two lines intersect.

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