one excellent way to get involved with construction projects that as you were learning is to volunteer

the sculpture i am pretty sure you are talking about is the statue b. the david statue now lives in the galleria dell'accademia, florence, italy. it was made by ‎michelangelo.

i believe the answer is  the similarity is that both are sacrifices which have the same purpose and sacrifice - jesus christ, but the difference is in offering of that sacrifice.

the similarity is that both are sacrifices which have the same purpose (repenting our sins) and sacrifice - jesus christ.  the difference is in the way of the offering that sacrifice. the sacrifice of jesus on the calvary is sacrifice of his actual living body and blood, but the sacrifice of the mass is the sacrifice of the jesus through bread (body) and blood (wine). in the sacrifice on calvary jesus was offered for us; while at mass he offers himself through us.