Macro to Delete Rows based on Specific Conditions

Hi,

I have a page of paralell lines. The slopes are listed in column A. I need to make a macro that keeps only the lines that match the first 3 slopes.

Please see the attached worksheet.

So, in the worksheet attached, the only lines that would be left after running the macro would be the ones with slopes of -0.04, -0.03 and -0.18. I've highlighted them for clarity.

What's the best approach to this. Is it even possible?