How can we help?

You can also find more resources in our Help Center.

Algebra Terms

Terms to memorize for Algebra I
STUDY
PLAY
Mixed Number
the sum of a whole number and a fraction
Line
straight line that has no width and no ends
Line Segment
part of a line
Intersect
when two lines cross
Point of Intersection
the place where two lines cross
Parallel Lines
lines in the same plane that do not intersect and the distance between the lines is always the same
Perpendicular
when two lines make square corners at the point of intersection
Right Angles
the angles made by perpendicular lines
Straight Angle
two right angles that forms a straight line back to back
Acute Angle
an angle smaller than a right angle
Obtuse Angle
an angle larger than a right angle
Polygon
simple, closed, flat geometric figures whose sides are line segments and whose lines do not cross
Triangle
a polygon with 3 sides and vertices
Quadrilateral
a polygon with 4 sides and vertices
Pentagon
a polygon with 5 sides and vertices
Hexagon
a polygon with 6 sides and vertices
Heptagon
a polygon with 7 sides and vertices
Octagon
a polygon with 8 sides and vertices
Nonagon
a polygon with 9 sides and vertices
Decagon
a polygon with 10 sides and vertices
Undecagon
a polygon with 11 sides and vertices
Dodecagon
a polygon with 12 sides and vertices
Concave
an indentation
Concave Polygon
a polygon with an indentation
Convex Polygon
any polygon without an indentation
Equilateral Polygon
when all the sides of a polygon have the same length
Equiangular Polygon
when all the angles of a polygon have the same measure
Regular Polygons
when all the sides of a polygon are the same length and all the angles are the same measure
Tick Marks
marks used to denote sides and angles that have the same length and/or measure
Right Triangle
a triangle with a right angle
Acute Triangle
a triangle with angles smaller than 90 degrees
Obtuse Triangle
a triangle with an angle that is greater than 90 degrees
Equianglular Triangle
a triangle in which all the angles are the same measure
Isoceles Triangle
a triangle that has at least two sides of equal length
Equilateral Triangle
a triangle in which the length of all the sides are equal
Scalene Triangle
a triangle in which all sides are different
Parallelogram
a quadrilateral that has two pairs of parallel sides
Trapezoid
a quadrilateral that has exactly two parallel sides
Rectangle
a parallelogram with four right angles
Rhombus
an equilateral parallelogram
Square
a rhombus with four right angles
Perimeter
the measure around
Radius
the distance from the center of the circle to the outside edge
Diameter
the distance from one side of a circle through the center to the other side
Circumference
the perimeter of a circle
Irrational Number
a number that would take an infinite number of digits to express
Number
an idea that represents quantity
Numeral
a symbol which represents the idea of a particular number
Value
the number represented by a numeral
Natural Numbers
counting numbers
Positive Real Numbers
any number that can be used to describe a physical distance greater than zero
Zero
a number that can be used to describe a physical distance of no magnitude
Real Numbers
all the positive real numbers plus zero
Negative Numbers
the negative counterparts of the positive real numbers
Signed Numbers
numbers that are indicated with signs of postive or negative used in algebraic addition
Symbol of Equality
the equal sign which indicates that two quantities are equal
Symbol of Inequality
the unequal sign which indicates that two quantities are not equal
Addend
the numbers added in an addition problem
Sum
the result of an addition problem
Minuend
the first number in a subtraction problem
Subtrahend
the second number in a subtraction problem
Difference
the result of a subtraction problem
Factor
the numbers multiplied in a multiplication problem
Product
the result of a multiplication problem
Dividend
the first number in a division problem
Divisor
the second number in a division problem
Quotient
the result of a division problem
Numerator
the number on the top of a fraction
Denominator
the number on the bottom of a fraction