Here's why:

* Stratovolcanoes, also known as composite volcanoes, are tall, conical volcanoes built up by many layers (strata) of hardened lava and tephra (ash, cinders, and volcanic bombs).

* Tajumulco is known for its steep slopes and its history of explosive eruptions, both characteristics of stratovolcanoes.

* Its summit is also a complex of lava domes, another feature common in stratovolcanoes.

Let me know if you have any other questions!