If u=pi(r+h),find r when u=16 1/2 and h=2
solve this question by taking the value of pi 22/7

U=π(r+h)
r+h=U/π
r=U/π  - h

Data: 
U=16  1/2=16  +  1/2=(16*2+1)/2=33/2
h=2
π=22/7

Then: 
r=U/π  - h
r=(33/2)/(22/7)   -   2
r=(33*7)/(2*22)   -   2
r=231 /44   -   2
r=(231-2*44)/ 44
r=(231-88)/44
r=143/44   =   (3*44  + 11)/44=3  11/44

r=143/44      or    3  11/44

U =  π* (r + h )   [ : π

The answer is