Geographical map reading in junior high school

180-degree longitude is zero-degree longitude. 1. Measure the included angle between zero meridian and any point (0- 180 degrees), which is the local longitude value. 2. Determine the east-west longitude. If any point is at the zero meridian, the clockwise direction of the pointer is the west longitude, and vice versa.

Question 2

Solar terms can be judged by measuring the angle between the sun's rays and the earth's equator, and the rays passing through the center of the earth's sphere are the direct points.