What gives objects their resistance

[WavesOfPhysics]

some objects of the same material can be broken applying different amounts of strenght in a certain way, and this goes back directly to their shape and their mass.
and to break any object we have to put an amount of pressure sufficient enough and in the optimum places to get the best results, but how does the mass and the shape of the object influence it's resistance to pressure therefore giving it 'strenght' ?
any mathematical formulas would be of great help besides the literal describtion

 

[Simon Bridge]

In general, the ability to avoid breaking under load scales with the cross-section area.
I think the concepts you are looking for will fall around the idea of "tensile strength" and "brittleness" - go look.

In general - material properties is a complicated field - the strength of an object depends on how it is made as well as what it is made out of and it's shape, for instance. If you are looking for a simple formula - you won't find one.