theorems page two Flashcards
triangle midsegment theorem
The segment connecting the midpoints of two sides of a triangle is parallel to the third side and is half as long as that side
triangle longer side theorem
if one side of a triangle is longer than the other side than the opposite angle the larger side is larger than the angle opposite the shorter side
triangle larger angle theorem
if one angle of a triangle is larger than another angle then the opposite side of the larger angle is larger than the side opposite the smaller angle
triangle inequality theorem
The sum of the lengths of any two sides of a triangle is greater than the length of the third side
hinge theorem
if two sides of one triangle are congruent to two sides of another triangle, and the included angle of the first is larger than the included angle of the second and the third side of the first longer than the third side of the second
Converse of the hinge theorem
if two sides of one triangle are congruent to two sides of another triangle and the third side of the first is longer than the third side of the second in the included angle of the first is larger than the included angle of the second
polygon interior angles theorem
The sum of the measures of the interior angles of a convex n-gon is (n-2)•180
corollary to the polygon interior angles theorem
The sum of the measures of the interior angles of a quadrilateral is 360
polygon exterior angle theorem
The sum of the measures of the exterior angles of a convex polygon one angle at each vertex is 360
parallelogram opposite sides theorem
if a quadrilateral is a parallelogram than its opposite sides are congruent
parallelogram opposite angles theorem
if a quadrilateral is a parallelogram then it’s opposite angles are congruent
parallelogram consecutive angles theorem
if a quadrilateral is a parallelogram then it’s consecutive angles are supplementary
parallelogram diagonals theorem
if a quadrilateral is a parallelogram then it’s diagonals bisect each other
parallelogram opposite sides converse
it’s both pairs of opposite sides of a quadrilateral are congruent then the quadrilateral is a parallelogram
parallelogram opposite angles converse
if both pairs of opposite angles of a quadrilateral are congruent then the quadrilateral is a parallelogram