An arch is not stable until what feature is in place?

Which is a good guideline to follow when evaluating art

In areas where even the experts disagree; everyone has a right to his own opinion. i mean if answers aren’t given just like in lots of things; then it has to be just anyone’s opinion. is this dualism multiplicity relativism or commitment

Why did bramante’s plans for the st. peter’s basilica never come to fruition? a. he and the pope could not agree on the plans. b. the pope changed his mind several times. c. the pope died and political unrest followed. d. bramante died before he could act on the plans.