WGU Math for Educators D128 Exam Questions and Verified Answers 2026/27 Graded A+
Adjacent - Next to
Irregular Polygon - A polygon whose sides are not all equal and whose angles have
different measures
Central Angle - Shape formed when 2 lines of rays meet with vertex; only at the center
point of the circle
Legs - The sides of a right triangle not opposite the right angle
Isosceles triangle - A triangle with two equal sides and two equal corresponding angles
Center - The point from which all the points on a circle are equidistant
Pentagon - A polygon with 5 sides and 5 angles
Bisect - To divide into two equal parts
Square - A quadrilateral with four equal sides and four 90 degree angles
,Diameter - The distance from one side of a circle to the other side that passes through the
center point
Vertical Line - A line that runs up and down on the coordinate plane, parallel to the y-axis
Parallelogram - Quadrilateral with opposite, parallel, equal sides and equal opposite
angles
Y-axis - The vertical line that passes through the origin on a coordinate plane
Equilateral triangle - A triangle with three equal sides and three angles of 60 degrees each
Regular polygon - A polygon with equal sides and equal angles
Degrees - The units in which angles are measured
Perpendicular - Describes lines intersecting each other to form a 90 degree or right angle
Coordinate plane - A tool used for graphing that is a display of a two dimensional plane
Vertex - A point where two line segments meet to form an angle
, Trapezoid - Quadrilateral with one pair of parallel opposite sides
Parallel - Two lines, line segments, rays or planes that are the same distance from one
another and never intersect
Right angle - An angle of 90 degrees
Supplementary angles - Two angles whose sum is equal to 180 degrees
Ray - A line with a single endpoint that extends infinitely in the other direction
Quadrilateral - A flat shape with four straight sides and four angles
Interior angle - An angle inside a shape between two joined sides
Line segment - Shortest distance between two points; completely straight with two
endpoints
Acute angle - Angles less than 90 degrees
Congruent - Figures with the same size and shape
Adjacent - Next to
Irregular Polygon - A polygon whose sides are not all equal and whose angles have
different measures
Central Angle - Shape formed when 2 lines of rays meet with vertex; only at the center
point of the circle
Legs - The sides of a right triangle not opposite the right angle
Isosceles triangle - A triangle with two equal sides and two equal corresponding angles
Center - The point from which all the points on a circle are equidistant
Pentagon - A polygon with 5 sides and 5 angles
Bisect - To divide into two equal parts
Square - A quadrilateral with four equal sides and four 90 degree angles
,Diameter - The distance from one side of a circle to the other side that passes through the
center point
Vertical Line - A line that runs up and down on the coordinate plane, parallel to the y-axis
Parallelogram - Quadrilateral with opposite, parallel, equal sides and equal opposite
angles
Y-axis - The vertical line that passes through the origin on a coordinate plane
Equilateral triangle - A triangle with three equal sides and three angles of 60 degrees each
Regular polygon - A polygon with equal sides and equal angles
Degrees - The units in which angles are measured
Perpendicular - Describes lines intersecting each other to form a 90 degree or right angle
Coordinate plane - A tool used for graphing that is a display of a two dimensional plane
Vertex - A point where two line segments meet to form an angle
, Trapezoid - Quadrilateral with one pair of parallel opposite sides
Parallel - Two lines, line segments, rays or planes that are the same distance from one
another and never intersect
Right angle - An angle of 90 degrees
Supplementary angles - Two angles whose sum is equal to 180 degrees
Ray - A line with a single endpoint that extends infinitely in the other direction
Quadrilateral - A flat shape with four straight sides and four angles
Interior angle - An angle inside a shape between two joined sides
Line segment - Shortest distance between two points; completely straight with two
endpoints
Acute angle - Angles less than 90 degrees
Congruent - Figures with the same size and shape
