30 terms

mbuttslphsTEACHER

triangle angle sum theorem

the sum of the measures of a triangle is 180

exterior angle theorem

the measure of an exterior angle of a triangle is the sum of the measures of the two remote interior angles

remote interior angles

two angles not adjacent to the exterior angle

corollary

a theorem with a proof that follows as a direct result

triangle angle sum corollary

the acute angles of a right triangle are complementary

acute triangle

3 acute angles

equiangular triangle

all angles are congruent

obtuse triangle

1 obtuse angle

right triangle

1 right angle

equilateral triangle

all sides are congruent

isosceles triangle

exactly 2 congruent sides

scalene triangle

no congruent sides

CPCTC

corresponding parts of congruent triangles are congruent

third angles theorem

If two angles of one triangle are congruent, the third angles are congruent

reflexive property of congruence

congruent to itself

symmetric property of congruence

can be written in either order

transitive property of congruence

if a is congruent to b and b is congruent to c then a is congruent to c

angle bisector

splits an angle into 2 congruent parts

midpoint

splits a segment into 2 congruent parts

SSS

All three sides are congruent in a triangle

SAS

two sides and their included angle are congruent in another triangle

ASA

two angles and their included side are congruent in another triangle

AAS

two angles and a non-included angle are congruent in another triangle

HL

the hypotenuse and leg of a right triangle are congruent to another right triangle

isosceles triangle theorem

if two sides of a triangle are congruent then the angles opposite those sides are congruent

converse of the isosceles triangle theorem

if two angles of a triangle are congruent then the sides opposite those angles are congruent

vertex angle

angle with the sides that are legs of an isosceles triangle

legs of an isosceles triangle

two congruent sides in a triangle

base angles

two angles formed by the base and the congruent sides of a triangle

equilateral triangle corollary

a triangle is equilateral if an only if it is equiangular (each angle measures 60 degrees)