Respuesta :

Volcanoes are formed by magma working its way to the surface. When the magma erupts (now lava) it will flow and ash will fall down. When the lava cools the volcano will grow. This process keeps repeating. Eventually the volcano will be huge.
Most volcanoes are formed by the movement of tectonic plates on the surface of the earth, and magma works its way up and turns into lava!

Hope this helps! Have a nice day/night