Calculating the Intersection Volume of Two Intersecting Cylinders

[Vadim]

the question i have in my assignment is this :
"Find the volume common to two circular cylinders each with radius r if the axes of the cylinders intersect at right angles"

now, I'm not even sure what they're asking, let alone where to begin.
not looking for answers, just a nudge in the right direction

 

[JFo]

The question is asking to find the volume of the part where the two cylinders "overlap."

for a picture of what this might look like, check out the the first picture (top left) in the link below

http://mathworld.wolfram.com/SteinmetzSolid.html

 

[whozum]

Hint: write out the equations of the cylinders and find intersection points.