Why is the black sea called black

the Black Sea wascalled "inhospitable" before Greek colonization, because it was difficult to navigate, and because its shores were inhabited by savage tribes, and that the name was changed to "hospitable" after the Milesians had colonized, as it were making it part of the Greek civilization

The sea was first named by the ancient Greeks who called it "Inhospitable Sea." The sea got this reputation because it was difficult to navigate, and hostile tribes inhabited its shores. Later, after the successful development of the coast by Greek colonists, the sea was renamed "Hospitable Sea."

the answer is blue river

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225