the himalaya mountains are an example of a mountain chain formed at which type of boundary

The Himalayas are a classic example of a convergent plate boundary, specifically a continental-continental collision. It happens when two massive tectonic plates—in this case, the Indian plate and the Eurasian plate—smash into each other. Since both plates are made of continental crust and are relatively buoyant, neither one wants to subduct deep into the mantle. Instead, the crust just gets all crumpled up, folded, and pushed sky-high.

I've seen some pretty rugged landscapes in my time, but the scale of the Himalayas is just insane. Because of that constant pressure from the two plates pushing against one another, those mountains are actually still growing a little bit every year. It’s wild to think that what’s now a massive peak used to be part of the sea floor before the plates started their slow-motion wreck.