3d Shapes

Solid geometry studies three-dimensional shapes, such as cubes, cylinders, and spheres. The diagrams show examples of these shapes.\(\quad\)\(\quad\) \(\quad\)

A surface is the exterior of a three-dimensional shape.

A face is a flat surface of a three-dimensional shape.

An edge is a line segment where two faces meet.

A vertex is a point where two or more edges meet.

When drawing 3D shapes, some edges are hidden because they are at the back of the shape. We call these hidden edges. To show the shape clearly, we use dotted lines for hidden edges. This helps us see the shape and its depth.

Name	Shape	Faces	Edges	Vertices
Cube		6 (flat)	12	8
Sphere		1 (curved)	0	0
Square Pyramid		5 (flat)	8	5
Cylinder		3 (1 curved, 2 flats)	0	0

A multi-view projection is a way to draw a 3D shape using 2D views. You show how the shape looks from different sides, like the front, right, and top, to help understand its form.

A net is a flat 2D shape that can be folded along its edges to form a 3D solid. Dashed lines show where to fold.