There are various methods for solving problems in solid geometry. Two of the most popular are the so-called construction method and the vector-coordinate method. Each is useful in its own way. The knowledge that will be offered in this chapter is of a general cognitive nature, but both methods will be used throughout the text to solve interesting problems and will often be compared, showing their advantages and disadvantages. Upon studying the section on polyhedral angles and their properties, the reader will have practice in proving important theorems and solving problems. Chapter 1 should help students who are struggling in multivariate calculus to understand the importance and significance of the dot product, cross product, or scalar triple product by applying them to solving problems in solid geometry. It teaches the reader to think geometrically.