How can we help?

You can also find more resources in our Help Center.

triangle

a polygon with three sides

scalene

no sides are congruent

isoscles

two sides are congruent

equilateral

all sides are congruent

acute triangle

three acute angles

right triangle

one right angle

obtuse triangle

one obtuse angles

equilangular triangle

three congruent angles

triangle sum theorm

the sum of the measures of the interior angles of a triangle is 180 degrees

exterior angles theorm

the measure of an exterior angles of a triangle is equal to the sum of the measures of the two nonadjacent interior angles

collary to a theorm

a statement that can be proved easily using a theorm

collary to the triangle sum theorm

the acute angles of a right angle are complementary

third angles congruence theorm

if two angles of one triangle are congruent to two angles of another triangle, then the third angles are congruent

SSS congruence postulate

if three sides of one triangle are congruent to three sides of a second triangle, then the two triangles are congruent

SAS congruence postulate

If two sides of one triangle are congruent to two sides and the included angle of a second triange, then the triangles are congruent

HL congruence postulate

if the hypotenuse and leg of a right triangle are congruent to the hypotenuse and leg of a second right triangle, then the two triangles are congruent

ASA congruence postulate

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 triangles are congruent

AAS congruence theorm

if two angles and the non included side f only riangle are congruent to two angles and the corresponding non included side of a second triange, the the triangles are congruent