We know that
1 m = 100 cm
Then to change from meter to centimeter, multiply by 100
Since the tree in Bob's backyard is 8.5 m
Then to change it to cm, multiply 8.5 by 100
[tex]\begin{gathered} 1m=100cm \\ 8.5m=8.5\times100 \\ 8.5m=850cm \end{gathered}[/tex]The height of the tree is 850 cm