Even though I have never heard of Slant Vis being given in any forecast, actual or pirep and in 35 years of driving airframes have never heard it discussed exept in relation to DME vs Flight alt. and being that at the range refered to and slant angle being 3 deg that the difference would be very small- fer gawd's sake - instead of being sarcastic why not just say:
A squared + B squared = C squared?
feel free to critique my grammar and punctuation.