So the formula to workout the area of a rectangle is height X width
so 11/3 x 5/8
which is 55/24 ft if they want a mixed number then... 2 
hope this helps
Because there is no solution if any number divide by 0
Answer:
21.62m
Step-by-step explanation:
first draw the the pipe
second you need know wich is the angle between the pipe and the corner
β=Tan^-1(6/9)=33.7
find the components using tow triangles
a=9/cos(33.7)=10.81m
b=6/sen(33.7)=10.81m
finally sum the leghts
L=10.81+10.81=21.62mm
attached procedure