Bihar receives an average annual rainfall of approximately 1000-1200 mm. The rainfall pattern varies between the plains and the Himalayan foothills in the north.

Total length of Ganges = 2525 km. Length in Bihar = 2525 × (1/3) ≈ 841.67 km ≈ 842 km. The Ganges flows through Bihar for a significant portion of its course.

Khudiram Bose, a revolutionary from Bihar, was imprisoned in the Cellular Jail (Andaman) for his role in nationalist activities. He became a symbol of anti-colonial resistance.

Dharmapal, a Pala dynasty ruler, established the Vikramashila University in the 8th century as a renowned center for Buddhist learning and philosophy.

Ajatashatru caves are located in Rajgir, which is in Nalanda district. These caves are associated with early Buddhist monks and monastic life.

Population density = Total population / Total area = 100,000,000 / 94,163 ≈ 1062 per km². Bihar has one of the highest population densities in India.

The Mahabodhi Temple is constructed primarily of bricks in the ancient Buddhist architectural style, dating back to the 5th-6th century. It is a UNESCO World Heritage Site.

Sher Shah Suri built the Shergarh fort as part of his fortification strategy. He was known for his administrative reforms and military architecture during his rule in the 16th century.

Chirand, located in Saran district, is an important archaeological site that has provided evidence of Paleolithic and Neolithic settlements in Bihar.

Vikramashila University was founded by Dharmapala, the Pala king, in the 8th century CE as a major center of Buddhist learning and research.