Answer:
5 m
Step-by-step explanation:
We know the volume of a cylinder is given by the expression
[tex]V= \pi r^2 h[/tex]. Let's replace what we know, and find the missing data:
[tex]785 = \pi r^2 \times 10 \rightarrow r^2 = \frac {785}{10\pi} = 25\\r= 5[/tex]
Taking only the positive value of the square root since it's a length.