scalar: a quantity that has size but no direction.
scalene triangle: a triangle with three unequal sides.
secant: a line that intersects a circle or a curve in two places.
secant: the reciprocal of the cosine.
second: the unit of measure of an angle that is 1/60 of a minute.
sector: a region bounded by two radii of a circle and the arc whose endpoints lie on those
radii.
segment: the union of a point, A, and a point, B, and all the points between them.
series: the sum of a sequence.
set: a well defined group of objects.
similar: two polygons are similar if their corresponding sides are proportional.
simoultaneous equations: a group of equations that are all true at the same time.
sine: in a right triangle, the length of a side opposite an angle divided by the length of the
hypotenuse of the triangle.
skew: two lines that are not in the same plane.
slope: the slope of a line is the change in the vertical coordinates/the change in the
horizontal coordinates of any two points on the line.
solid: a three dimensional object that completely encloses a volume of space.
sphere: the set of all points in space that are a fixed distance from a given point.
square: a quadrilateral with four equal sides and four 90 degree angles.
square root: of a number, x, is the number that, when multiplied by itself gives the
number, x.
subset: A set, B, is a subset of another set, A, if every element in B is also an element of
A.
sum: the result of adding.
supplementary: two angles are supplementary if their sum is 180 degrees.
symmetric: two points are symmetric with respect to a third point if the segments joining
them to the third point are equal. Two points are symmetric with respect to a
line if the line is the perpendicular bisector of the segment joining the points.