Based on the information given, it can be seen that the length or the book will be 20cm.
How to solve perimeter.
From the information given, Leena read a book that had a perimeter of 72 cm and one side of the book is 16 cm. Therefore, the length will be calculated thus:
Perimeter = 2(Length + Width)
72 = 2(Length + 16)
72 = 2L + 32
2L = 72 - 32
2L = 40
L = 40/2
L = 20
Therefore, the length is 20cm.
Learn more about perimeter on:
https://brainly.com/question/16596982
