Warm UpHow many corners does the tissue box have? How many flat surfaces? How many folded creases?Draw a net for the tissue box.

Corners: 8Flat Surfaces: 6Creases: 12

Space Figures and Cross Sections

Objectives:• To recognize polyhedrons and their parts.• To visualize cross sections of space figures.

Vocabulary^

• Why do we study the parts of a ployhedron?We can analyze a three-dimensional figure by using the relationship among its vertices, edges, and faces.

polyhedron

Problem1~

Euler’s Formula

Using Euler’s Formula

12

30

Practice*

Cross Section~

Practice*

Drawing a Cross Section

Practice*

Homework

• P692: 6, 8, 9, 11, 12, 14, 18-23