Explanation:
in triangle pqr and trs
statement reason
1. pr=rt ( s ) 1. given
2. angle prq = angle srt (a) 2. vertically opposite angle
3. rq = sr ( s ) 3 .given
4 triangle pqr ~= triangle trs 4. by SAS axiom/fact
5. pq = st 5. from statement 4
6. pq\\st 6. from statement 5
proved