Is 20 prime or composite tell me the factors

What two criteria are needed for triangles to be similar

For how answer my question this will be the last question can you answer in math subject

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?