theorems page 2 Flashcards
reflections in intersecting Lines theorem
if lines K and M intersect at point P, then a reflection in-line K followed by a reflection in line M is the same as a rotation about. P. The angle of rotation is 2X , where X is the measure of the acute or right angle formed by lines K and M
triangle sum theorem
The sum of the measures of the interior angles of a triangle is 180
exterior angle theorem
The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles
corollary to the triangle sum theorem
The acute angles of a right triangle are complementary
third angles theorem
if two angles of one triangle are congruent to two angles of another triangle then the third angles are also congruent
Side – angle – side congruence theorem
if two sides and the included angle of one triangle are congruent to two sides and the included angle of a second triangle then the two triangles are congruent
bass angles theorem
if two sides of a triangle are congruent then the angles opposite of them are congruent
Converse of the base angles theorem
if two angles of a triangle are congruent then the sides opposite them are congruent
corollary to the base angles theorem
if a triangle is equal lateral then it is equiangular
corollary to the converse of the base angles theorem
if a triangle is equiangular then it is equal lateral
Side – side – side congruence theorem
if three sides of one triangle are congruent to three sides of the second triangle then the two triangles are congruent
hypotenuse – leg congruence theorem
if the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and leg of a second right triangle then the two triangles are congruent
angle – Side – angle congruence theorem
if two angles and the included side of one triangle are congruent to two angles and the included side of a second triangle then the two triangles are congruent
angle – angle – side congruence theorem
if two angles and did not included Side of one triangle are congruent to two angles any corresponding non-included side of the second triangle then the two triangles are congruent
perpendicular bisector theorem
any point if a point lies on the perpendicular bisector of a segment then it is equidistant from the endpoints of the segment