C-15-Q078mediumsingle_mcq△ABC\triangle ABC△ABC এর ∠C\angle C∠C সূক্ষ্ম এবং AD⊥BCAD\perp BCAD⊥BC; AB2=?AB^2 = ?AB2=?aAC2+BC2−2BC⋅CDAC^2+BC^2-2BC\cdot CDAC2+BC2−2BC⋅CDbAC2+BC2+2BC⋅CDAC^2+BC^2+2BC\cdot CDAC2+BC2+2BC⋅CDcAC2−BC2AC^2-BC^2AC2−BC2dAC2+2BC2AC^2+2BC^2AC2+2BC2