Schyrlet Cameron & Carolyn Craig 
Geometry Basics, Grades 5 — 8 [PDF ebook] 

Geometry Basics for grades 5 to 8 targets the basic geometry concepts students need to understand and perform operations involved in higher-level math. In this standards-based series, students are given practice with lines, angles, circles, perimeter, area, volume, two-dimensional figures, and three-dimensional figures. Mark Twain Media Publishing Company specializes in providing engaging supplemental books and decorative resources to complement middle- and upper-grade classrooms. Designed by leading educators, this product line covers a range of subjects including math, science, language arts, social studies, history, government, fine arts, and character.