I want to make a customized channel with all the dimesnions fixed - except A and G (variables). See attached screen shot please.
Any help will be much appreciated.
Your screenshot seem to come from Autocad. Is your question related to Autocad.
If your question is related to Inventor, you should model one instance of your part. And then go to manage Author, Create Ipart. You will be able to select parameters (select the dimensions you want to drive), then you can create a table with different lines where you assign different values to each of your selected parameters.