C-03-Q040mediumsingle_mcq△ABC\triangle ABC△ABC এ ∠B=60°\angle B = 60°∠B=60° হলে নিচের কোনটি সঠিক?aAC2=AB2+BC2AC^2 = AB^2 + BC^2AC2=AB2+BC2bAC2=AB2+BC2−AB⋅BCAC^2 = AB^2 + BC^2 - AB \cdot BCAC2=AB2+BC2−AB⋅BCcAC2=AB2+BC2+AB⋅BCAC^2 = AB^2 + BC^2 + AB \cdot BCAC2=AB2+BC2+AB⋅BCdAC2=AB2−BC2+AB⋅BCAC^2 = AB^2 - BC^2 + AB \cdot BCAC2=AB2−BC2+AB⋅BC