Page 130 - Math Genius C3

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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 some terms used to understand solid shapes before we study them
in detail.

plane and curved surface

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

Some objects have only Some objects have only Some objects have both
plane or flat surfaces. curved surfaces. plane and curved surfaces.

Faces, edges and Vertices of a solid

Face: The surface of a solid shape is called its face. It can be plane or curved.

Edge: The line where two faces meet is called an edge. It can be straight or curved.
Vertex
Vertex: The point at which the edges meet is called a corner or vertex. Face
Edge
cube cuboid

 It has 6 square faces (plane).  It has 6 rectangular faces (plane). The opposite
 It has 8 vertices or faces have the same shape and size.
Face
corners.  It has 8 corners.
Face
 It has 12 straight edges Edge  It has 12 straight edges,
of the same size. Corner opposite edges are Edge Corner

Example: Dice equal.
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. Plane Edge
curved face meets with Plane face  It has one vertex. face

its plane faces. Curved face  It has one curved edge, where the curved
 It has no vertex. Edge face meets with its plane face.

Example: Cold drink can Example: Ice-cream cone

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