If angle A and angle B are acute angles such that cos A = cos B, then show that angle A = angle B.

It is given that, cos A =  cos B
                                                                                 

       Therefore, AC/AB = BC/AB
                        By Cancelling AB
        we get, AC = BC
        As we know angles opposite to equal sides are equal.
                        angle A = angle B

                    HENCE PROVED