For example:
The latitude of Zhengzhou is 34:44 north latitude, which means 34 degrees 44 minutes north latitude. At the vernal equinox (March 20 or 2 1), the direct point of the sun is at the equator of the earth, that is, the latitude is 0.
Then the noon sun altitude angle in Zhengzhou on this day is 90 degrees-34 degrees 44 minutes, which is 55 degrees 16 minutes.