How to find Polaris with the help of Ursa Major? (scientific questions)

The positions of Ursa major and Cassiopeia in the sky are just opposite each other across the Polaris. For those of us who live in the mid-latitude area of the northern hemisphere, in spring, shortly after dark, the Big Dipper is in the northeast and Cassiopeia is in the northwest; In May and June, shortly after dark, the Big Dipper appeared near the top of the head, and Cassiopeia was near the true north horizon. In other months, when Cassiopeia is in the northeast and close to the top of the head, it is the turn of the Big Dipper to approach the northwest and north horizons. In the area north of the Yellow River Basin in China, these two constellations can be seen in the sky at the same time all year round. In the area south of the Yangtze River basin, sometimes only one of them can be seen. When one constellation is near the top of the head, the other is just below the northern horizon, so it can't be seen. How to use Ursa Major to find Polaris? First, find the outermost two stars of the Big Dipper, Shu Tian and Tian Xuan, and connect them with imaginary lines. Extend this place from Tian Xuan to Shu Tian about five times, and you will meet a bright star, namely the North Star. In that part of the sky, there is only one star as bright as Polaris, so it is easy to find. Of the five main bright stars in Cassiopeia, three are relatively bright. Along the middle of these three stars and a small star in front of it, the distance is extended by more than three times, which is the position of the North Star. If you find Polaris, you will find true north, and other directions will be easily determined. Face north, back south, right east and left west. The height of Polaris on the horizon is similar to the local geographical latitude. Therefore, if you know the height of Polaris in a certain place, you can roughly know the geographical latitude of this place. Source: Reading and Composition (Senior Primary School Edition)