the correct question is
The radius of a cylinder is 5" and the lateral area is 70pi sq. in. Find the length of the altitude.
we know that
[surface lateral area]=(2*pi*r)*height
height= [surface lateral area]/(2*pi*r)
surface lateral area=70*pi in²
r=5 in
so
height= [70*pi]/(2*pi*5)------> 7 in
the answer is
7 in