Answer:
The methods of relative dating of rocks include:
c. superposition
d. cross-cutting relationships
e. original horizontality
These principles are fundamental concepts in geology that help geologists determine the relative ages of rock layers and structures without providing numerical ages. The other options mentioned are not methods of relative dating:
a. original angularity and f. angular relationships are more related to the initial orientation of rock layers, which can be significant in certain geological contexts but are not used for relative dating.
b. radiometric dating is a method of absolute dating, providing numerical ages of rocks based on the decay of radioactive isotopes.