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Solids are not flat like plane figures. They are 3-dimensional shapes/figures. Solid shapes
have length, breadth (or width) and depth (or height). A solid occupies a fixed amount
of space. Let us learn about the terms used in the understanding of solid shapes before

explaining the solid shapes.
plane and curved Surface

The part of an object which we see, touch and feel is known as the Surface. The Surface
can be plane (or flat) or curved.

Some objects have only the Some objects have only the Some objects have both the
plane surface. curved surface. plane and curved surface.

Faces, edges and Vertices of a Solid

Face: The Surface of a solid shape is called its face. The face of a solid could be plane or curved.

edge: The line where two faces meet is called an edge. The edge of a solid could be
straight or curved. Vertex
Face
Vertex: The point where edges meet is called a corner or vertex. Edge

cube cuboid

 It has 6 square faces (plane).  It has 6 rectangular faces (plane). The opposite

 It has 8 vertices or faces are of the same shape and size.
corners. Face  It has 8 corners.
 It has 12 straight edges Edge  It has 12 straight edges. Face
of the same size. opposite edges are Edge
Corner
 Example: Dice. equal. Corner
 Example: Shoebox

cylinder cone

 It has two similar plane faces (its top and  It has one plane face Vertex
base) and one curved face. (its base) and only Curved face
 It has two equal curved edges where the one curved face.
curved face meets with Plane face  It has one vertex. Plane Edge
face
its plane faces. Curved face  It has one curved

 It has no vertex. Edge edge, where the curved face meets with its
 Example: Cold drink can plane face.
 Example: Ice cream cone.

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