Were Umar ibn Al-Khattāb and Brahmagupta alive at the same time?
Yes. Umar ibn Al-Khattāb and Brahmagupta were alive at the same time, from c. AD 598 to AD 644.
Yes. Umar ibn Al-Khattāb and Brahmagupta were alive at the same time, from c. AD 598 to AD 644.