Astronomy Paper

The textbook for Chapter 4 begins on page 103.
The link to the textbook is : https://assets.openstax.org/oscms-prodcms/media/documents/Astronomy-OP_zItt6LJ.pdf?_gl=1*wgsby6*_ga*ODExNDUwNDk5LjE2NzM2NjQ2NDQ.*_ga_T746F8B0QC*MTY3MzczNTk4Ny4yLjEuMTY3MzczNjUzNC40MC4wLjA.