How to display a 1-inch line on mobile?

问题

I'm desigining a mobile website for a hamburger parlor. They have varying width of hamburgers, from 3 inches to 3 feet in diameter (no kidding).

Of course, people don't expect a "normal size" hamburger to be 10 inches large (which is!), and they expect the here-usual 3-5 inches.

So what I'd like to do is to display one or two inches on the screen (Android and iOS), and a meter under the picture of the hamburger.

I don't want to build a mobile app if possible, just a "mobile edition" of a webpage.

Any ideas?

来源：https://stackoverflow.com/questions/12273358/how-to-display-a-1-inch-line-on-mobile