This Instructional Activity is a part of the Lesson 18, Unit 6, Grade 7. In this problem, students must visualize the different types of triangles that can be sliced from a right rectangular prism. With your group, discuss whether a right rectangular prism can be sliced at an angle so that the resulting slice looks like the figure in Figure 1. If it is possible, draw an example of such a slice into the following prism. Once students have had some time to attempt Example 1, pose the following questions: Is it possible to make a triangular slice from this prism?