HELP IF YOU ARE GOOD AT MATH PLEASE!!!!

Drag an expression or phrase to each box to complete the proof.
It is given that RSTU is a parallelogram, so RU | ST by the definition of parallelogram. Therefore, 21 22 by the alternate
interior angles theorem, and m/1 m/2 by the
It is also given that 21 and 23 are
complementary, so m21+m23-90° by the
and so 2 and
By substitution, m/2+1
are complementary by the definition of complementary
definition of complementary angle congruence postulate
21
4
23 m21 m23
= 90°,