Final answer:
Igneous, sedimentary, and metamorphic rocks are the three types of rocks that can be found in a roadcut.
Step-by-step explanation:
Based on how rocks are formed, geologists classify them into three basic types: igneous, sedimentary, and metamorphic. Igneous rocks form when magma or lava cools and solidifies. Sedimentary rocks form when broken pieces of other rocks from weathering processes get cemented together. Metamorphic rocks are pre-existing rocks that are altered by heat and pressure.