A:
If
one enters the masjid while the Imam is prostrating, one must recite, while standing, Takbirat-ul-Ihram (saying: ''Allahu Akbar [Allah is the Greatest]'' upon starting Prayer), recite Takbir of prostration, and then sit with Ma'mums. After the Imam's Taslim, the latecomer should complete the Rak`ah missed, as the Rak`ah is valid only when joining the Imam during Ruku' (bowing) not sujud, i.e. prostration.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.