Megasthenes, the Greek ambassador, wrote in his Indica about Pataliputra (modern Patna) being one of the greatest and most prosperous cities in the ancient world during the Mauryan period.

The statue of Manjushree in Vaishali is one of the tallest statues in Bihar, standing approximately 22 meters high. It was constructed to commemorate the Buddhist heritage of the region.

The Rajmahal Hills in Bihar are known for their scenic landscape along the Ganga River. However, the question might refer to the Rajgir hills (not Rajmahal), which are more important pilgrimages sites associated with Buddha.

Calculation: 1000 mm × 60% = 1000 × 0.60 = 600 mm. This represents the average monsoon rainfall in Bihar, which significantly impacts agriculture and water resources.

Vaishali district in Bihar is home to the ruins of the ancient Vaishali republic, one of the world's oldest republics. It was the capital of the Lichchavi clan and had a democratic form of governance.

Mahatma Gandhi led the Champaran Satyagraha in 1917 against indigo planters in Champaran, Bihar. Though Gandhi was not from Bihar, this movement was conducted in Bihar and is a significant part of its freedom struggle history.

The Ganga Action Plan was launched in 1985 by the Indian government to clean the Ganga River. Bihar is significantly affected as the Ganga flows through the state, and several cities like Patna depend on it.

The Ashoka Rock Edict XIII, which contains his famous Kalinga War message and the conversion of Ashoka to Buddhism, is located at Rajgir in Bihar, an ancient city with Buddhist significance.

The Battle of Buxar (1764) was fought near Patna between the East India Company and a coalition of Mir Qasim (Nawab of Bengal), Shuja-ud-Daulah (Nawab of Awadh), and Mir Jafar (former Nawab). It established British dominance in northern India.

Madhubani district is world-famous for its traditional Mithila or Madhubani painting, an ancient art form recognized by UNESCO as a Masterpiece of the Oral and Intangible Heritage of Humanity.