Given: FS⊥SM; RM⊥SM; ∠1≅∠2
Prove: ∠F≅∠R
Statement:
1. FS⊥SM; RM⊥SM (Given)
2. ∠FSM=90บ and ∠RMS=90บ
3. ∠FSM≅∠RMS
4. ∠1≅∠2
5. SM≅SM
6. ΔSRM≅ΔMFS
7. ∠F≅∠R (CPCTC)

A)2. Definition of congruent angles; 3. Vertical angle theorem; 4. Given; 5. Reflexive; 6. SSS

B)2. Definition of perpendicular lines; 3. Definition of congruent angles; 4. Given; 5. Reflexive; 6. ASA

C)2. Definition of perpendicular lines; 3. Vertical angle theorem; 4. Given; 5. Reflexive; 6. SAS