Cutting measured sections out of cylinder

[gbwsmith95]

Hi all,

I am trying to create a cylinder that is 26 foot to the out side edge and is 2mm thick, and then extruded to 3 meter, this part is easy, but...

I then need to have 3 x 3 meter (along the circumference) cut outs in one half of the sphere.. please see images for reference. so I am struggling to find how to measure the 3 meter wide along circumference cut out outs??

Thanks

[TheCADWhisperer]

You can define parameter for arc length based on PI and radius.