@PROFDOCDIGITALLIBRARIES
WGU D128 Math Exam for Educators-with 100% verified
solutions-2025 Latest Version ||
Complete Guide A+
Sum of a polygon
(n-2)180
Right angle
90 degrees
PR
acute angle
less than 90 degrees
obtuse angle
O
greater than 90 degrees and less than 180 degrees
FD
reflex angle
greater than 180 degrees
O
complementary angles
Two angles whose sum is 90 degrees
C
supplementary angles
Two angles whose sum is 180 degrees
interior angles of a polygon
angles inside of a polygon
triangle
A polygon with three sides whose interior angles equal 180.
, @PROFDOCDIGITALLIBRARIES
isosceles triangle
A triangle that has 2 equal sides.
equilateral triangle
a triangle with 3 equal sides (60 degrees)
Triangle Inequality Theorem
The sum of the lengths of any two sides of a triangle must be greater than the length of the third
side
PR
scalene triangle
no equal sides
O
quadrilateral
a four-sided polygon with interior angles adding to 360 degrees
FD
Parallelogram
A quadrilateral with two pairs of parallel sides
O
square
A quadrilateral with 4 sides that are equal and has all 90 degree angles
C
rectangle
a parallelogram with 4 right angles
Rhombus
A parallelogram with four congruent sides.
Trapezoid
A quadrilateral with exactly one pair of parallel sides
WGU D128 Math Exam for Educators-with 100% verified
solutions-2025 Latest Version ||
Complete Guide A+
Sum of a polygon
(n-2)180
Right angle
90 degrees
PR
acute angle
less than 90 degrees
obtuse angle
O
greater than 90 degrees and less than 180 degrees
FD
reflex angle
greater than 180 degrees
O
complementary angles
Two angles whose sum is 90 degrees
C
supplementary angles
Two angles whose sum is 180 degrees
interior angles of a polygon
angles inside of a polygon
triangle
A polygon with three sides whose interior angles equal 180.
, @PROFDOCDIGITALLIBRARIES
isosceles triangle
A triangle that has 2 equal sides.
equilateral triangle
a triangle with 3 equal sides (60 degrees)
Triangle Inequality Theorem
The sum of the lengths of any two sides of a triangle must be greater than the length of the third
side
PR
scalene triangle
no equal sides
O
quadrilateral
a four-sided polygon with interior angles adding to 360 degrees
FD
Parallelogram
A quadrilateral with two pairs of parallel sides
O
square
A quadrilateral with 4 sides that are equal and has all 90 degree angles
C
rectangle
a parallelogram with 4 right angles
Rhombus
A parallelogram with four congruent sides.
Trapezoid
A quadrilateral with exactly one pair of parallel sides
