Pls help I’ll brainlest

:calculate the sum of the interior angles of a 13-sided polygon.

Most countries in the middle east must import a majority of their a. gasoline b. oil c. food d. water

Ascientist is explaining how background cosmic radiation gives evidence of the big bang theory. she says that radiation has been detected everywhere equally as heat in the universe and is increasing. this has been shown to be residual radiation from the big bang. what error did the scientist make?