Chapter 5 1st Quiz Flashcards
Scalene
No congruent sides
Isosceles
At least 2 congruent sides
Equilateral
All sides congruent
Acute
3 acute angles
Obtuse
1 obtuse angle
Right
1 right angle
Equiangular
All angles congruent
Equilateral is _____ isoceles
Always
Isosceles is ______ equilateral
Sometimes
△ΣT (Triangle Sum Theorem)
Sum measures of interior angles of a triangle is equal to 180 degrees
Exterior Angle Theorem (EAT)
The measure of exterior angles of a triangle is equal to the sum measure of two remote interior angles
Right Triangle Corollary
Acute angles of right triangles are complementary
How do you prove triangles are congruent?
Use the definition of congruent triangles.
Third Angle Theorem
If two angles of one triangle are congruent to two angles of another triangle, then third angles are also congruent.
Side-Angle-Side Theorem (SAS)
Official Definition
If two sides and included angle of one triangle are congruent to two sides and the included angle of a second triangle, then the triangles are congruent.