###
perpendicular lines

Two lines that intersect to form right angles

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intersecting lines

lines that cross at one point

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parallel lines

lines in the same plane that never intersect

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vertex

The common endpoint of an angle

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congruent

Having the same size,length or angle measure

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polygon

a closed 2-dimensional shape formed by three or more straight line segments.

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trapezoid

a quadrilateral with exactly 1 pair of parallel sides

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parallelogram

A quadrilateral opposite sides are congruent and parallel,no right angles

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rectangle

a parallelogram with 4 right angles

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rhombus

a parallelogram with 4 congruent sides,no right angles

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square

a parallelogram with 4 right angles and 4 congruent sides

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isosceles triangle

a triangle with two congruent sides

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obtuse triangle

a triangle with 1 angle greater than 90 degrees

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equilateral triangle

A triangle with 3 congruent sides and 3 congruent angles

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scalene triangle

a triangle with no congruent sides

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right triangle

a triangle with one 90 degree angle

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acute triangle

A triangle with three angles less than 90 degrees.

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quadrilaterals

a polygon with four sides,the general term

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pentagon

a five-sided polygon

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hexagon

a polygon with 6 sides

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octagon

A polygon with 8 sides

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regular polygon

a polygon with all sides and all angles equal or congruent

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faces

flat/plane polygons that make up the sides of a 3-dimensional solid

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vertices

points or corners of a polygon or 3-dimensional solid

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edges

a line segment where two faces meet on a 3-dimensional solid

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net

a 2-dimensional representation of a 3-dimensional solid

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area

The number of square units needed to cover a given polygon

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dimensions

The length, width, and height of an object being measured.

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surface area

The sum of all the areas of all the faces of a 3-dimensional solid.

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volume

The amount of space inside a 3-dimensional solid measured in cubic units.

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