Examples of websites using
Futura
(Futura is a sans-serif font designed by Paul Renner and released by Linotype in 1936. It is available in various styles with different weights and matching italics)
with
Avenir
(Avenir is a sans-serif font designed by Adrian Frutiger and Nadine Chahine, released by Linotype in 1988. It features clean and modern letterforms and is available in multiple weights and styles)