Catching one Rak`ah of the congregational Maghrib Prayer

A: if a person arrives at the final Rak‘ah of the Maghrib Prayer, he should join the Imam in it, and when the Imam pronounces Taslim (salutation of peace ending the Prayer), he should stand to offer another Rak‘ah; sit to recite the first Tashahhud; stand to offer the third Rak‘ah; sit to recite the final Tashahhud and then pronounce Taslim.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.