Octahedron
An octahedron is a three-dimensional geometric shape that has eight triangular faces, twelve edges, and six vertices. Each face of an octahedron is an equilateral triangle, meaning all three sides are of equal length.The octahedron is one of the five Platonic solids, which are convex polyhedra with equivalent faces, equal angles, and the same number of faces meeting at each vertex. The other Platonic solids are the tetrahedron, cube (or hexahedron), icosahedron, and dodecahedron.To calculate the surface area of an octahedron, use the formula:\[A = 2 \times \sqrt{3} \times s^2\]Where \(s\) represents the length of a side of one of the equilateral triangles.To calculate the volume of an octahedron, use the formula:\[V = \frac{1}{3} \times \sqrt{2} \times s^3\]Where \(s\) represents the length of a side of one of the equilateral triangles.Study Guide: Octahedron
.◂Math Worksheets and Study Guides Eighth Grade. Solving equations and inequalities
Study Guide
Solving equations and inequalities 
Worksheet/Answer key
Solving equations and inequalities Worksheet/Answer key
Solving equations and inequalities Worksheet/Answer key
Solving equations and inequalities
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyThe resources above cover the following skills:
Algebra (NCTM)
Represent and analyze mathematical situations and structures using algebraic symbols.
Develop an initial conceptual understanding of different uses of variables.