Final answer:
Sedimentary strata are typically formed horizontally through the principle of original horizontality.
Step-by-step explanation:
Yes, sedimentary strata are typically formed horizontally. This is known as the principle of original horizontality. According to this principle, sedimentary layers are originally deposited in horizontal or nearly horizontal positions. The oldest layer is usually found at the bottom, and as newer layers are deposited on top, they maintain their horizontal orientation.