Is the prayer of someone who didn`t face Quibla (Ka`ba direction) valid?
                                All perfect praise be to Allah,The Lord of The Worlds.                                                                                                                                                              Facing the Quibla is a condition for the validity of prayer, and the prayer of the person who hadn`t faced the direction of the Quibla is invalid, and he is obliged to repeat it. And Allah Knows Best.
                             
                        
                            
                                
                                A woman used contraceptive pills, and her menses exceeded (15) days, is it permissible for her to fast?
                                The maximum of menstrual blood is (15) days, but if it exceeded that due to a medication, or the like, then it is Istihadah (bleeding outside the monthly period), and in this case she should perform Ghusl (ritual bath), pray, and fast. Moreover, she is obliged to make up for the missed fasting days which exceeded her regular menses. And Allah Knows Best.
                             
                        
                            
                                
                                Is it permissible for a woman to shake hands with her brother-in-law?
                                It is forbidden for the woman to shake hands with her brother-in-law because he isn`t a Mahram (unmarriageable) of hers.
                             
                        
                            
                                
                                Is it permissible for a man to marry up to four wives (polygamy in Islam) for pleasure although he can`t afford that?
                                It is desirable for the man to have one wife if there was no need for him to have more, if he can't afford marriage forthcoming expenses.