19. Complete the paragraph proof.
Given: 21 and 22 are supplementary, and 22 and 23 are supplementary.
Prove: <123
>
By definition of supplementary angles, mz1+ m22=
Then, mz1+m22=m22+ m23 by the
get mz1 =
(d), or 212
(e).
(a) and mz2+ m23 =_________(b).
(c). Subtract m/2 from each side. You
