Power Plant
in celedon city
dowsing machine
After you get the part go to the Power Plant and give it to the guy near the machine
Inside Cerulean Gym, by the innertubes on the left side.
Robbie Fowler
Get the machine part from the team rocket grunt at ceruleun gym.
Return the missing part to the Powerplant He will then let you in
Area of rectangle with part of the shape missing = area of rectangle (lengthxwidth)-area of missing part.
First go to the power plant to hear about the missing part, go to the gym to fid the thief, follow and fight him to find where the part is and return it to the power plant. Then go to the cape to interrupt mistys date. She will then be at the gym to battle you
If you have already been to the powerplant then head back to Cerulean city and walk to the gym. A team rocket grunt will come out and run off (follow him to the nugget bridge). Battle him and he will tell you the part is in the gym. Go back to the gym again and go to the north western most pile of inner tubes and search them (you will find the machine part). Go back to the power plant and give the part to the manager and you are finished.
In kanto, go to the power plant. They'll tell you about a missing machine part. Then, go to the bridge south of Cerulean. A team rocket dude will say he hid it in the gym. Go all the way to the back of the gym and to the left, then down to where the tubes are and start looking! BTW, dowsing machine won't help ;)
The Machine Part for the power plant is located in the water at the Cerulean City gym in the very small square pool to be exact. Press A at the water to use Surf then check each spot of the water by pressing A you should eventually find it.