90 degrees up. At the equator, Polaris is on the horizon. For every degree of latitude that you move toward the N pole, Polaris shifts 1 degree higher above the horizon. The other stars seem to rotate around it. This is a result of the Earth's rotation.
Some stars stay above the horizon and never set.
These are the circumpolar stars . They are called noncircumpolar . Angular distance above the horizon. Measured with a simple sextant. Angular distance around the horizon from the North.