What's the minimum degree by which an octagon can rotate to map onto itself

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

Which of the following is the true for f(x) = 5cos

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?