How many corners does a box have? This 3rd grade count edges of 3D shapes worksheet turns that question into a careful counting game. Eight solids are drawn on a grid. Dashed lines show the hidden back of each shape. For every drawing, your child writes the number of faces, edges and vertices on three short lines. The set mixes prisms and pyramids with round shapes, like a cylinder and a cone. Page two is the answer key, with all 24 numbers filled in.