A 3D shape with all straight edges and flat faces is a polyhedron. Other 3D shapes with least one curved surface are not polyhedra. A 3D shape with regular polygonal faces, meeting at equal angles, is ...

Everyone learns the number one rule about triangles in high school: the angles of a triangle add up to 180 degrees. But did you know that sometimes they don't? Triangles are much more interesting than ...

The net of a 3D shape is what it looks like if it is opened out flat. There are many types of nets for the different 3D shapes. A net is made from polygons that can be folded and joined to make a ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and to develop students' reasoning with properties of triangle to develop students' ...

Over the last two years, mathematicians have identified the best versions of a child’s playroom’s worth of shapes. These results occupy a quirky corner of math and, fittingly, have been produced by ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and develop students' reasoning with properties of different classes of triangles to ...