Which area was part of lands acquired within 25 years of muhammeds death

The Arabs conquered the Byzantine territories of Syria and Palestine during that period, including the important cities there, Jerusalem and Damascus, and soon conquered Egypt. Persia was completely conquered in the short term.

Explanation:

During these great conquests and successes, the powerful Meccan clan succeeded in establishing a hereditary Caliph power, thus creating the Ummayad dynasty with its capital in Damascus. The Ummayad dynasty continued with spectacular conquests, so they expanded the Arab Empire  to Spain and Morocco to the west, and to the Indus Valley to the east.