How were the Himalayan mountains formed?

The Himalayas were formed as a result of the collision between the Indian Plate and the Euroasian Plate.

Explanation:

The Himalayan mountain range is the world's tallest mountain range (8,848 m) which stretches between India, Pakistan, Nepal, and China.

Approximately 200 million years ago, India was an island floating near the coast of Australia. As Pangea was breaking apart, India was moving northwards. Later, the part of the Indian tectonic plate went under the Eurasian landmass, moving it up, which resulted in the rise of the Himalayas. So, instead of descending with the plate, the Indian tectonic plate pushed Eurasian landmass upwards and created a massive mountain range - The Himalayas.

Even until now, the Himalayan mountain range rises by 1-2 cm per year.