Is the following definition of complementary angles reversible? If yes, write it as a true biconditional

Question

Complementary angles are two angles whose sum measures to 90 degrees

- The statement is not reversible
- Yes, if angles are complementary, then their sum measures to 90 degrees
- Yes, angles are complementary if (and only if) their sum measures 90 degrees (My answer)
- Yes, angles are complementary if their sum measures to 90 degrees

Which biconditional is not a good definition?

Two angles are supplementary if and only if the sum of their angles measure 180.
Two angles are vertical angles if and only if they are nonadjacent and are formed by two intersecting lines.
Two angles from a linear lair if and only if the angles are adjacent. (my Answer)
The sum of two angles is 90 if and only if they are complementary

Answer 1

Answers are good.

Typing, not so much . . .

Answer 2

lol thank you sorry in a hurry

One more please

The true conditional statement "If 1/2 (m<ABC) = m<ABD, then m<ABC = 2(m<ABD" illustrates which property of equality?

A. Addition property of equality
B. Subtraction property of equality
C. Multiplication property of equality (My Answer)
D. Division property of equality

Answer 3

since only multiplication was used, I'd say that's a good guess...

Unless you like dividing by 1/2 ...

Answer 4

Thanks.....