Definitions
What is the name of the property that says a segment or angle is congruent to itself?
Reflexive Property
The interior angles of a triangle add too...
180 degrees
Write a congruency statement using sides AB and CD
AB = CD
If a triangle has an angle with a measure of 80, and another angle with a measure of 40, what is the measure of the third angle?
60 degrees
True or False. In a right triangle, the hypotenuse is located across from the right angle.
True
What does bisects mean?
Cuts in half
What does it mean if C is the midpoint of segment AD?
C is the middle point of the segment. AC is congruent to DC.
If all three sides of one triangle are congruent to all three sides of a second triangle, what postulate are these triangles congruent by?
SSS Postulate
If triangle ABC is congruent to triangle DEF, what angle in triangle DEF is <B congruent to?
<E
If two legs in a right triangle are congruent to the two legs in another right triangle, what theorem is used to prove the triangles are congruent?
LL Theorem
What do perpendicular lines form?
90 degree angles, right angles
What does the Alternate Interior Angle Theorem say?
If two lines are parallel, and cut by a transversal, then the alternate interior angles are congruent.
If two sides and the included angle of triangle are congruent to the two sides and the included angle of a second triangle, what postulate are these triangles congruent by?
SAS Postulate
If side AB with measure 4x + 10 is congruent to side CD with measure 2x - 6. What is x?
-8
If the hypotenuse and an acute angle of one right triangle are congruent to the hypotenuse and corresponding acute angle of another right triangle, what theorem proves the triangles are congruent?
HA Theorem
What does CPCTC mean?
Congruent Parts of Congruent Triangles are Congruent - all angles and sides are congruent
the two remote/ opposite interior angles
If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, what postulate proves these triangles are congruent?
ASA Postulate
Given a pair of corresponding angles, one with a measure of -2x - 2, and the other with a measure of -9x +12, what is x?
x = 2
If one leg and an acute angle of one right triangle are congruent to the corresponding leg and acute angle of another right triangle, what theorem proves the triangles are congruent?
LA Theorem
Name three pairs of congruent angles located on a transversal.
corresponding angles, alternate interior angles, alternate exterior angles, consecutive interior angles, vertical angles
What does the Third Angle Theorem say?
If two angles of one triangle are congruent to the two angles of a second triangle, then the third angles are congruent.
If two angles and a nonincluded side of one triangle are congruent to the corresponding two angles and side of a second triangle, what theorem proves these two triangles are congruent?
AAS Theorem
The two angles opposite the exterior angle of a triangle measure 25 and 35 degrees. What is the measure of the exterior angle?
60 degrees
If the hypotenuse and a leg of one right triangle are congruent to the hypotenuse and corresponding leg of another right triangle, what theorem proves the triangles are congruent?
HL Theorem