Can you tell me the method to figure this Astronomy question out?

Question

On March 21, noon in Seattle the sun would be how high in the sky in degrees?

Tell me how you find the answer, show me the science behind this so I can figure out these questions, thanks.

Answer 1

March 21 is the approximate date of the spring equinox. This is significant because at the equinoxes the sun at noon is directly over head (that is, at an altitude of 90°) at local noon. As you move north from the equator, the sun gets lower in the sky in proportion to how far north you are. At ten degrees north, the noon sun is ten degrees south of the zenith, at an altitude of 80°. Seattle is at latitude 47°35', so the sun at noon on the solstice is at (90° - 47°35'), or 42°25' above the horizon. That assumes that by noon you mean local noon. Noon by the clock is not the same thing, especially now that daylight savings time begins in early March; the sun at noon PDT will be a little lower than 42°25'. For that, your best option is to consult an online almanac.

Answer 2

March 21 is the vernal equinox, when the Sun is on the celestial equator. The celestial equator is 90 degrees south of the north celestial pole. The altitude of the north celestial pole is equal to your latitude. So you need to know the latitude of Seattle. And you also need to know that any altitude over 90 degrees is past the Zenith (the point directly over head at altitude 90 degrees), and so at some lower altitude in the other direction. For example at 30 degrees latitude, the pole altitude is 30 and the equator would be 30+90=120 degrees above the northern horizon, which is to say 180-120=60 degrees above the southern horizon.