This is the title. The second question, how to draw ... The exercise from the seventh grade math book 1 1.2 by Shanghai Education Publishing House is on page 100. Don't ask me, this topic is
This is 60.
This is 120.
This is 240.
This is 360.
This figure can be seen as a big circle and four small semicircles. You can connect these circles into a line and rotate the line, so it's easy to understand.