Polyhedron
/ˌpɑːliˈhiːdrən/
Definition 1 of 1
Pro Tip 1/3Visualize Shapes
Imagine a 3D object with flat surfaces to understand polyhedra better. 
When someone mentions a polyhedron, picture a dice in your mind.
Pro Tip 2/3Math Context
Polyhedron is a term often used in geometry, relating to shapes with straight edges. 
In our geometry class, we learned that each face of a polyhedron is a polygon.
Pro Tip 3/3Not Round
Remember, unlike spheres, every polyhedron has flat faces; they're not curved. 
Balls are not polyhedrons because they have curved surfaces, not flat ones.