Download Triangle Angle Sum Theorem:

Triangle Angle Sum Theorem: For a triangle, the interior angle sum = 180
2 corollaries to the Triangle angle sum thm: (little theorems that easily follow from a theorem)
The acute angles of a right triangle are complementary
The angles of an equiangular triangle are all 60
3rd Angle Theorem:
If two angles of one triangle are congruent to two angles of another triangle, then the 3rd angles are congruent.
Exterior Angle Theorem:
In a triangle, an exterior angle is equal to the sum of the two remote interior angles.
Definition of congruent triangles
Two triangles are congruent i.f.f. all six corresponding sides and angles are congruent
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