What is algorithm? What formulas, theorems, equations and hints must I use?

Any hints? =)

Minkowski addition.

Thx
Really, if we can find A-B then we must understand that [0,0] belong to A-B or not
If 'yes' then answer = max{0, dist([0,0], A-B) - 60}
If 'no' then answer = 0