Net A pattern used to construct a polyhedron.

Nonagon A polygon with 9 sides.

Number Line A pictorial representation of a set of numbers.

Numerator The number of equal parts being considered in a whole or group: 5/7- The numerator is 5.

Obtuse Angle An angle whose measure is more than 90° but less than 180° .

Obtuse Triangle A triangle with 1 angle that measures more than 90° .

Octagon A polygon with 8 sides.

Octahedron A polyhedron with 8 faces.

Opposite Angles The equal angles formed by 2 intersecting lines.

Order of Operations The rules to be followed when simplifying expressions: 1.Brackets 2.Exponents 3.Division & Multiplication 4.Addition & Subtraction.

Ordered Pair A pair of numbers, (x,y), indicating the x & y coordinates of a point on a graph.

Origin Intersection of the horizontal & vertical axes on a graph. The origin is described by the coordinates (0, 0).

Outcome The result of an experiment.

Parallel Lines Lines in the same plane that never meet.

Parallelogram A quadrilateral with opposite sides parallel & equal in length.

Pentagon A polygon with 5 sides.

Percent (%) A fraction or ratio in which the denominator is 100.

Perfect Number A number whose factors, other than the number itself, add up to the number: 6 = 1 + 2 + 3.

Periods The groups of 3 digits separated by spaces in numbers with more than 4 digits: 123 456 789 contains 3 periods.

Perpendicular Lines Two lines that intersect at a 90° angle.

Perspective The different views of an object: top, bottom, side, front.

Pi ( p ) (3.1415) The quotient that results when the circumference of a circle is divided by its diameter.

Pictograph A graph that uses pictures or symbols to represent similar data.

Polygon A closed figure formed by 3 or more line segments.

Polyhedron A 3-dimensional figure having polygons as faces.

Polyomino A shape made of squares joined along whole edges.

Polyominoid A shape made by joining cubes face to face.

Power A number written in exponential form: 3².

Prime Factorization A composite number expressed as a product of prime factors:

Prime Number A number with exactly 2 different factors, 1 & itself: 3 = 1 x 3

Prism A polyhedron with 2 parallel & congruent bases in the shape of polygons. The other faces are parallelograms.

Probability The ratio of the number of ways an outcome can occur to the total number of possible outcomes.

Proper Fraction A fraction whose numerator is smaller than its denominator: 2/5.

Proportion An equation which states that 2 ratios are equal:

Pyramid A polyhedron with one base and the same number of triangular faces as there are sides on the base.

Quadrilateral A polygon with 4 sides.

Quotient A number resulting from division.

Radius The length of the line segment that joins the centre of a circle and a point on the circumference.

Range The difference between the highest & lowest in a set of numbers: (10 to 15)

Rate A comparison of 2 measurements with different units.

Ratio A comparison of two numbers: 4:5 .

Ray A part of a line. A ray contains one endpoint.

Reciprocals Two numbers whose product is 1.

Rectangle A quadrilateral with opposite sides parallel & equal in length, & four 90° angles.

Rectangle Prism A prism whose bases are congruent rectangles.

Reflection A flip transformation of an object in a mirror or reflection line.

Reflex angle An angle whose measure is more than 180 degrees & less than 360° degrees

Regular polygon A closed figure in which all sides and all angles are equal.

Regular polyhedron A 3-dimonional figure having identical regular polygons.

Repeating decimal A decimal where the digit or digits repeat without ending: 9/11 = 0.1818181818.

Rhombus A quadrilateral with opposite sides parallel and all 4 sides .

Right Angle An angle whose measure is 90 degrees.

Right bisector A line that divides another line into 2 congruent segments at a 90° .

Right Triangle A triangle with 1 angle that measures 90° .

Rotation A turn transformation of an object about a fixed point or turn center.

Rotational Symmetry A figure has rotational symmetry if it maps onto itself more than once in a complete turn.

Rounding A process of replacing a number by an approximate number.

Sample A selection from the total population available

Sample Size The number of items selected from the total population.

Scale Drawing An accurate drawing that is either an enlargement or a reduction of an actual object.

Scalene triangle A triangle with no sides equal.

Set A collection of objects and numbers.

Shell A 3-Dimensional object whose interior is empty.

Similar Figures Figures that have the same shape and not always the same size.

Simplest form The form of a fraction whose numerator & denominator have no common factors other than 1.

Skeleton A representation of the edges of a polyhedron.

Solid A 3-dimensonal object whose interior field is completely filled.

Square A quadrilateral with 4 equal sides & 4 right angles.

Standard form The way in which numbers are usually written. The value of each digit is not shown :435 000

Straight angle An angle whose measure is 180° .

Substitution The replacement of variable by a number.

Supplementary angles Two angles whose sum is 180 degrees.

Surface area The sum of the areas of the faces of a three-dimensional figure.

Survey A sample of information.

Tangram A square cut into seven shapes: 2 large triangles, 1 medium sized triangle, 2 small triangles, 1 square & a parallelogram.

Terminating decimal A decimal whose digits terminate: 3.154.

Tessellation A repeated pattern of geometric figures that will completely cover a surface.

Tetrahedon A polyhedron with 4 triangular faces.

Transversal A line that intersects parallel lines.

Trapezoid A quadrilateral with exactly 2 parallel sides.

Triangle A polygon with 3 sides.

Twin primes A pair of prime numbers that differ by 2: 17 and 19

Unit fractions Fractions that have 1 as their numerator.

Unit rate A comparison of 2 measurements in which the second term is 1:3m/1s of 3m/s.

Variable A letter or symbol used to represent a number.

Vertex The common endpoint of 2 rays or line segments.

Volume The number if cubic units contained in space.

Whole Numbers Numbers in the sequence 0,1,2,3,4,5,6,7,8,9,10...