#### Answer

The proof is in the following form:
Column 1 of proof; Column 2 of proof.
Thus, we have:
1. $RS \bot AB $ and $CB \bot AC$; Given
2. Angle RSB and angle BCA are 90 degrees; perpendicular lines form right angles
3. Angle RSB is congruent to angle BCA; right angles are congruent
4. Angle B is congruent to itself; Identity property
5. Triangle BSR is congruent to triangle BCA; AA