ACT MATH Vocabulary 2026. Exam Questions and Correct Answers With
100% Correct Answers | Latest 2026 |
absolute value - The value of a number without regard to its sign, expressed as a positive
number
Amplitude - Height of a wave from the middle line to the top of a hump
arc - a portion of the circumference of a circle
arithmetic mean - average
arithmetic sequence - a sequence in which each term is found by adding the same number
to the previous term
Asymptote - a line that a graph approaches but never crosses
average - the arithmetic mean of a group of values
average speed - total distance divided by total time
Axis - one of two perpendicular lines that define values in the coordinate plane
bisect - to divide into two equal parts
chord - A segment connecting two points on a circle; the diameter is the longest chord of a
circle
, circle - The set of all points in a plane that are the same distance from a given point called
the center
circle graph (pie chart) - a graph which represents percentages as slices of a circle
circumference - The total length of the outside edge (perimeter) of a circle.
Coefficient - A number multiplied by a variable in an algebraic expression.
Collinear - points that lie on the same line
Note that the line doesnt have to be literally drawn in the figure; this only means that you could
connect the points with a single straight line
combination - a calculation for determining the number of arrangements of a set when order
doesnt matter
complementary angles - Two angles whose sum is 90 degrees
complex number - a number of the form a+bi where a and b are real numbers and i is the
square root of -1
congruent - Having the same measure; can be said of segments, angles, triangles or any
shape
coordinate plane (Cartesian) - A two-dimensional system in which a location is described
by its distances from two intersecting, usually perpendicular, straight lines called axes. (x, y)
Cosecant (csc) - a trig function equivalent to hypotenuse/opposite. It is the reciprocal of
sine.
100% Correct Answers | Latest 2026 |
absolute value - The value of a number without regard to its sign, expressed as a positive
number
Amplitude - Height of a wave from the middle line to the top of a hump
arc - a portion of the circumference of a circle
arithmetic mean - average
arithmetic sequence - a sequence in which each term is found by adding the same number
to the previous term
Asymptote - a line that a graph approaches but never crosses
average - the arithmetic mean of a group of values
average speed - total distance divided by total time
Axis - one of two perpendicular lines that define values in the coordinate plane
bisect - to divide into two equal parts
chord - A segment connecting two points on a circle; the diameter is the longest chord of a
circle
, circle - The set of all points in a plane that are the same distance from a given point called
the center
circle graph (pie chart) - a graph which represents percentages as slices of a circle
circumference - The total length of the outside edge (perimeter) of a circle.
Coefficient - A number multiplied by a variable in an algebraic expression.
Collinear - points that lie on the same line
Note that the line doesnt have to be literally drawn in the figure; this only means that you could
connect the points with a single straight line
combination - a calculation for determining the number of arrangements of a set when order
doesnt matter
complementary angles - Two angles whose sum is 90 degrees
complex number - a number of the form a+bi where a and b are real numbers and i is the
square root of -1
congruent - Having the same measure; can be said of segments, angles, triangles or any
shape
coordinate plane (Cartesian) - A two-dimensional system in which a location is described
by its distances from two intersecting, usually perpendicular, straight lines called axes. (x, y)
Cosecant (csc) - a trig function equivalent to hypotenuse/opposite. It is the reciprocal of
sine.
