Page 233 - Math Smart - 7

If you look carefully at the prisms, you would notice that
O the faces of a prism are made up of 2 types of shapes. trapezoidal: in the shape
0 one of the shapes is the uniform cross-section of the prism. of a trapezium
0 the uniform cross-section of solid A is a triangle so it can be cut into many
triangles of the same shape and size.
0 the uniform cross-section of solid B is a trapezium so itcan be cut into many
trapeziums of the same shape and size.

A triangular prism has 5 faces. A trapezoidal prism has 6 faces.
3 faces are rectangles and 4 faces are rectangles and
2 faces are triangles. 2 faces are trapeziums.
It has a total of 6 vertices. It has a total of 8 vertices.
It has a total of 9 edges. It has a total of 12 edges.

In the prism on the right, the opposite faces opposite
are in the shape of a pentagon. faces
So, this prism is called a pentagonal prism.

This is another type of prism. Its opposite faces
opposite
are in the shape of a hexagon.
faces
So, it Is called a hexagonal prism.

Pyramids

The solids below are pyramids.
. vertex
vertex

triangular triangular
face
face
triangular
rectangular
base
base
V edges
edges
Rectangular pyramid Triangular pyramid

Notice that
a
0 pyramid does not have a uniform cross-section so it cannot be cut into
A triangular pyramid is
pieces of the same shape and size. also called a tetrahedron. ^
0 the slanted faces of a pyramid meet at a vertex at the top of the pyramid.
a
0 pyramid has a base.
a
0 pyramid is named after its base.
A rectangular pyramid has 5 faces. A triangular pyramid has4 faces.
1 face is a rectangle and 4 faces are triangles. All 4 faces are triangles.
There are 5 vertices. There are 4 vertices.
There are 8 edges. There are 5 edges.
The base of the pyramid is a rectangle. The base of the pyramid is a triangle.