Which property states that a + (b + c) = (a + b) + c?

commutative

associative

distributive

addition property of equality

Flashback to semester a. are triangles pqr and stu congruent? what is the congruency that proves they are congruent? what is the perimeter of triangle pqr? show your work.

Is the square root of 4 plus the square root of 16 rational?

D(5, 7). e(4,3), and f(8, 2) form the vertices of a triangle. what is mzdef? oa. 30° ob. 45° oc. 60° od 90°