S

Sampling   A method used to estimate probability by selecting a part of a larger group.

Scalene triangle A triangle with no two sides congruent.

Scientific notation   A method of expressing a number as the product of a power of  10 and a number between

1 and 10.

Sector (of circle) The region of a circle enclosed by two radii and the arc of the circle cut off by the radii

Segment   See line segment.

Semicircle   Half of a circle.

Set A collection of distinct objects (2) Sides (of angle) The rays which form the angle

Sides of a figure  The rays that form an angle or the segments that form a polygon.

Sides of an equation   The mathematical expressions to the right and to the left of the equals sign.

Sieve of Erastosthenes A method used to locate prime numbers less than a given number

Similar figures   Figures that have the same shape but not necessarily the same size.

Simple closed curve A closed curve whose representation meets itself only once, and that is at the beginning point

Simple form  A mixed number is in simple form if its fractional part is expressed in lowest terms.

Simplify an expression   To replace an expression with its simplest name.

Sine of an angle   If LA is an acute angle of a right triangle, the sine of LA sin A is the ratio of the length of the side opposite LA to the length of the hypotenuse.

Slope of a line   The steepness of a line; that is, of the change in the y-coordinate to the change in the x-coordinate when moving from one point on a line to another point.

Solid   An enclosed region of space bounded by planes.

Solution   A value of a variable that makes an equation or inequality a true sentence.

Solving a right triangle   The process of finding the measures of the sides and angles of a right triangle.

Sphere A figure in space made up of all points equidistant from a given point.

Square  A rectangle with all four sides congruent.

Square root of a number   One of the two equal factors of the number.

Standard form   A way of writing polynomials so that like terms are combined wherever possible, and the combined terms are arranged so that powers of the variable decrease from left to right.

Statistics The science of collecting, presenting, and interpreting data

Statistical measures   Measures including the range, mean, median, and mode used to analyze numerical data.

Stem-and-leaf plot   A data display that lists the last digits "leaves" of the data values to the right of the earlier digits "stems".

Straight angle An angle with a measure of 1800

Supplementary angles   Two angles whose measures have a sum of 180°.

Surface area   The total area of a solid.

Symmetric  ,  A figure is symmetric with respect to a line if it can be folded on that line so that every point on one side

System of equations   A set of two or more equations in the same variables.

System of notation The method of writing the numerals, or names of numbers

System of numeration Each set of basic symbols and the rules for combining them to name numbers