Note: The definitions included here are those that are used in the Saskatchewan Education document "Mathematics 6-9: A Curriculum Guide for the Middle Level".

Various mathematics dictionaries may have different definitions. These definitions are designed to be meaningful to middle level mathematics teachers.

abscissa

• the first element in a coordinate pair. When graphed in the coordinate plane, it is the distance from the y-axis. Frequently called the x coordinate.

acute angle

• an angle whose measure is between 0^o and 90^o.

acute triangle

• a triangle with three acute angles.

additive inverses

• two numbers whose sum is 0.

adjacent angles

• two angles that share a vertex and a common side between them but have no interior points in common.

< ABC and < CBD are adjacent.

algorithm

• a step-by-step procedure for carrying out computation.

alternate angles

• two angles that are in opposite locations when lines are cut by a transversal. If the angles are between the lines, they are called alternate interior angles; if they are outside the lines, they are called alternate exterior angles. If the lines are parallel, the alternate angles are congruent.

Alternate interior c and f d and e Alternate exterior a and h b and g

altitude

• length from the uppermost point of a triangle to the line opposite.

associative property

• when performing an operation on three or more numbers, the result is unchanged by the way the numbers are grouped. Addition and multiplication of numbers are associative since a+(b+c)=(a+b)+c and (ab)c=a(bc).

  i.e. 6 + (7 + 9) = (6 + 7) + 9 and (4 x 3) x 5 = 4 x (3 x 5).

• Subtraction and division are not associative.

i.e. (8 / 4) / 2 and 8 / (4 / 2) are not equal.

axis (axes)

• the horizontal and vertical lines that form the quadrants of the coordinate plane. The horizontal axis is usually called the x-axis. The vertical axis is usually called the y-axis.

base of a triangle

• any side of a triangle.

benchmarks

• points of reference used in estimation.

e.g. The square corner on a piece of paper can be used as a benchmark when estimating angle measures.

binomial

• a polynomial consisting of two terms.

e.g. 3x² - 8

bisector of an angle

• a segment or ray that divides an angle into 2 congruent angles.

bisector of a line segment

• a point, segment, ray or line that divides a line segment into 2 congruent segments.

box-and-whiskers plot

• a type of graph used in data management particularly useful in showing the spread of the distribution of the data.

broken-line graph

• a type of graph used in data management where the data points are joined by line segments.

Questions or comments about the glossary can be directed to TheCentralizer@MathCentral.uregina.ca or see About Us page for more information.