#### Answer

cm

#### Work Step by Step

This page is about 21 cm wide. Length can be measured in m, cm or mm. If we choose 21 m it will very long for the width of the page even 21 mm will be short. So 21 cm is the correct choice.

Published by
Pearson

ISBN 10:
0321825535

ISBN 13:
978-0-32182-553-7

cm

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