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Terms to memorize for Algebra I

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Mixed Number

the sum of a whole number and a fraction

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Line

straight line that has no width and no ends

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Line Segment

part of a line

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Intersect

when two lines cross

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Point of Intersection

the place where two lines cross

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Parallel Lines

lines in the same plane that do not intersect and the distance between the lines is always the same

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Perpendicular

when two lines make square corners at the point of intersection

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Right Angles

the angles made by perpendicular lines

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Straight Angle

two right angles that forms a straight line back to back

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Acute Angle

an angle smaller than a right angle

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Obtuse Angle

an angle larger than a right angle

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Polygon

simple, closed, flat geometric figures whose sides are line segments and whose lines do not cross

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Triangle

a polygon with 3 sides and vertices

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Quadrilateral

a polygon with 4 sides and vertices

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Pentagon

a polygon with 5 sides and vertices

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Hexagon

a polygon with 6 sides and vertices

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Heptagon

a polygon with 7 sides and vertices

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Octagon

a polygon with 8 sides and vertices

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Nonagon

a polygon with 9 sides and vertices

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Decagon

a polygon with 10 sides and vertices

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Undecagon

a polygon with 11 sides and vertices

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Dodecagon

a polygon with 12 sides and vertices

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Concave Polygon

a polygon with an indentation

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Convex Polygon

any polygon without an indentation

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Equilateral Polygon

when all the sides of a polygon have the same length

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Equiangular Polygon

when all the angles of a polygon have the same measure

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Regular Polygons

when all the sides of a polygon are the same length and all the angles are the same measure

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Tick Marks

marks used to denote sides and angles that have the same length and/or measure

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Right Triangle

a triangle with a right angle

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Acute Triangle

a triangle with angles smaller than 90 degrees

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Obtuse Triangle

a triangle with an angle that is greater than 90 degrees

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Equianglular Triangle

a triangle in which all the angles are the same measure

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Isoceles Triangle

a triangle that has at least two sides of equal length

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Equilateral Triangle

a triangle in which the length of all the sides are equal

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Scalene Triangle

a triangle in which all sides are different

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Parallelogram

a quadrilateral that has two pairs of parallel sides

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Trapezoid

a quadrilateral that has exactly two parallel sides

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Rectangle

a parallelogram with four right angles

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Rhombus

an equilateral parallelogram

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Square

a rhombus with four right angles

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Perimeter

the measure around

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Radius

the distance from the center of the circle to the outside edge

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Diameter

the distance from one side of a circle through the center to the other side

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Circumference

the perimeter of a circle

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Irrational Number

a number that would take an infinite number of digits to express

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Number

an idea that represents quantity

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Numeral

a symbol which represents the idea of a particular number

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Value

the number represented by a numeral

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Natural Numbers

counting numbers

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Positive Real Numbers

any number that can be used to describe a physical distance greater than zero

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Zero

a number that can be used to describe a physical distance of no magnitude

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Real Numbers

all the positive real numbers plus zero

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Negative Numbers

the negative counterparts of the positive real numbers

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Signed Numbers

numbers that are indicated with signs of postive or negative used in algebraic addition

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Symbol of Equality

the equal sign which indicates that two quantities are equal

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Symbol of Inequality

the unequal sign which indicates that two quantities are not equal

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Addend

the numbers added in an addition problem

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Sum

the result of an addition problem

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Minuend

the first number in a subtraction problem

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Subtrahend

the second number in a subtraction problem

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Difference

the result of a subtraction problem

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Factor

the numbers multiplied in a multiplication problem

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Product

the result of a multiplication problem

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Dividend

the first number in a division problem

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Divisor

the second number in a division problem

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Quotient

the result of a division problem

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Numerator

the number on the top of a fraction

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Denominator

the number on the bottom of a fraction