,3r

m ¦'$pj-;i

rm- ¦¦

1!

Mr

1'|;i" &::¦ 'i >

il

ISifii1

il'S ¦¦

mlip ^fe .•)

i;5!•:- ¦- ;

Describing Prismsand Pyramids

Cliiieic llewiew

> A pyramid has 1 base.The base is a face.A pyramid has some triangular faces.

This pyramid has 6 vertices,10 edges, and 6 faces:- 1 pentagon

s 5 triangles

This pyramid has 4 vertices,6 edges, and 4 faces:e 4 triangles

edge

base

face

vertex

face

vertex

A prism has 2 bases that are the same.

A prism has some rectangular faces.

This prism has 12 vertices,

18 edges, and 8 faces:

• 2 hexagons

• 6 rectangles

edge^

base^\

This prism has 8 vertices,

12 edges, and 6 faces:

• 6 rectangles

IV-vertex face

Tace edge

base

vertex

1. Colour the pyramids blue. Colour the prisms red.

96

E21

Practice' j

1. Complete the chart.

ObjectPyramid or

Prism?Numberof Faces

Number

of EdgesNumber

of Vertices

h

2. Name each object and the shapes of its faces.

Stretch Your Thinking

Draw the other base and the

faces of the prism with this base:

97

i!-S'mM'

litli'

^rr^ ^ jf::J ',!

f :l

p;!|ife |.11mp?: i,

tM ¦I1!fef

!¦¦ k ' " ¦kr'li. :

RKWii ¦ "- '© -'M j V; jmm'

Iliiiifel•I 11W''';' '•

ig}||j |[|!ipsliIkk!!

ii- li]kmpii'Is.Ptite;

iliKik:;P; 3Ki ^ IIWii • }i

Int-

IflA ¦

li!

i;} fft$ ¦ '

Quick Be¥iew

ObjectWumber of

VerticesNumber of

EdgesNumber of

Faces

^/\faceCone

1 1 1

face^ ) '¦_ }Cylinder

0 2 2

Sphere

0 0 0

Try These g ® e ® © « ©

1. Tell if each object looks like a cone, a cylinder, or a sphere,

a) b) c)

d)f ««

e) f)

liH ©8IT:

\

ractice l

1. Look at home for an item that looks like each object.

Draw a picture of each item and write its name.Tell how many vertices, edges, and faces the item has.

ItemWumber of

VerticesNumber of

EdgesNumber of

Faces

:ylinder

sphere

cone

2. Pietro says that a cylinder has more faces than edges. Is he correct?

Explain

Think about cylinders, cones, and spheres.Sketch 3 objects that together have:

a) 5 faces and 5 edges b) 1 face and 1 edge

99