They are both formed by erosion. They are both formed from cooled lava. Heat and pressure can turn them into lava. Heat and pressure can turn them into metamorphic rock.
I gave my students this multiple choice question: How are igneous and sedimentary rocks similar?

Only one answer is correct among these 4 choices:
- They are both formed by erosion.
- They are both formed from cooled lava.
- Heat and pressure can turn them into lava.
- Heat and pressure can turn them into metamorphic rock.

Could you tell me which one is correct?

Heat and pressure can turn them into metamorphic rock.