Vocabulary
A quadrilateral with both pairs of opposite sides parallel
What is a parallelogram
two angles with measures that have a sum of 180 degrees
What are supplementary angles
The segments that connect nonconsecutive vertices of a polygon
What are diagonals
How many diagonals are in a heptagon?
What is 14
The following formula comes from?
( (x1+x2)/2 , (y1+y2)/2 )
What is the midpoint theorem
How many important properties of a parallelogram are there?
What is 4
the line segment that divides the angle into two equal parts.
What is an angle bisector
A line segment with endpoints that are a vertex of the triangle and the midpoint of the side opposite the vertex
What is a median
Find how many sides this regular polygon has, given an interior angle measure of 160?
What is 18
The measure of an exterior angle of a triangle is greater than the measure of either of its corresponding remote interior angles.
What is the Exterior Angle Inequality Theorem
The point of concurrency of the angle bisectors of the triangle
What is an incenter
A segment from a vertex of a triangle to the line containing the opposite side and perpendicular to that side
What is an altitude of a triangle
three or more lines that intersect at a common point
What are concurrent lines
What is the measure of an exterior angle of a regular hendecagon/unidecagon/undecagon?
What is 32.72
The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.
What is the Triangle Inequality Theorem
The point of concurrency of the altitudes of the triangle
What is an orthocenter
the same distance between two objects
What is equidistant
the point of congruency of the medians of a triangle
What is a centroid
What is the sum of measures of the interior angles of a 23-gon
What is 3780
The sum of the exterior angle measures of a convex polygon, one angle at each vertex, is 360.
What is Polygon Exterior Angle Sum Theorem
The point of concurrency of the perpendicular bisectors of the sides of a triangle.
What is a circumcenter
a line that passes through the midpoint of a segment and is perpendicular to that segment
What is a perpendicular bisector
a line segment that goes from one vertex to another inside a polygon. The vertices can not be next to each other.
What is diagonal
Which regular polygon has the property that the measure of its interior angles is half the measure of its exterior angles.
What is a regular triangle or an equilateral triangle
The sum of the interior angle measures of an n–sided convex polygon is (n – 2) ⋅ 180.
What is Polygon Interior Angle Sum Theorem