WGU D128 Math Exam for Educators with Complete Solutions

Sum of a polygon - ANSWER-(n-2)180 Right angle - ANSWER-90 degrees acute angle - ANSWER-less than 90 degrees obtuse angle - ANSWER-greater than 90 degrees and less than 180 degrees reflex angle - ANSWER-greater than 180 degrees complementary angles - ANSWER-Two angles whose sum is 90 degrees supplementary angles - ANSWER-Two angles whose sum is 180 degrees interior angles of a polygon - ANSWER-angles inside of a polygon triangle - ANSWER-A polygon with three sides whose interior angles equal 180. isosceles triangle - ANSWER-A triangle that has 2 equal sides. equilateral triangle - ANSWER-a triangle with 3 equal sides (60 degrees) Triangle Inequality Theorem - ANSWER-The sum of the lengths of any two sides of a triangle must be greater than the length of the third side scalene triangle - ANSWER-no equal sides quadrilateral - ANSWER-a four-sided polygon with interior angles adding to 360 degrees Parallelogram - ANSWER-A quadrilateral with two pairs of parallel sides square - ANSWER-A quadrilateral with 4 sides that are equal and has all 90 degree angles rectangle - ANSWER-a parallelogram with 4 right angles Rhombus - ANSWER-A parallelogram with four congruent sides. Trapezoid - ANSWER-A quadrilateral with exactly one pair of parallel sides isosceles trapezoid - ANSWER-a trapezoid whose nonparallel opposite sides are congruent kite - ANSWER-a quadrilateral with two pairs of adjacent sides congruent and no opposite sides congruent Hypotenuse - ANSWER-the side of a right triangle opposite the right angle legs of a right triangle - ANSWER-the sides adjacent to the right angle Pythagorean Theorem - ANSWER-a²+b²=c² acute angle on a right triangle - ANSWER-90 degrees circle - ANSWER-The set of all points in a plane that are the same distance from a given point called the center diameter - ANSWER-the distance across a circle through its center Radius - ANSWER-The distance from the center of a circle to any point on the circle Tangent - ANSWER-A line in the plane of a circle that intersects the circle in exactly one point. circumference - ANSWER-The distance around a circle Circumference of a circle - ANSWER-C=2πr or C=πd area - ANSWER-The space inside the shape Area of a circle - ANSWER-A=πr² Arcs - ANSWER-a part of the circumference of a circle. sector - ANSWER-The part of a circle that looks like a piece of pie. A sector is bounded by 2 radii and an arc of the circle. Solving for angles and arcs - ANSWER-Central angle/360•=arc length/2πr= area of sector/πr² central angle - ANSWER-Vertices are on the center of the circle inscribed angle - ANSWER-an angle whose vertex is on the circle