Question

how are lakes formed on the mountains

Answer 1

river forms from water moving from a higher altitude to a lower altitude, all due to gravity. When rain falls on the land, it either seeps into the ground or becomes runoff, which flowsdownhill into rivers and lakes, on its journey towards the seas.

Answer 2

The lakes may be formed in many ways. High on the mountainsides, glaciers carved out smooth bowls called cirques. Many were formed of glaciers, and these same glaciers will eventually fill them in. High above the lakes, the action of weathering and erosion is slowly wearing down the mountains.