To help you get a visual of this let's start off with basics.... remember that ---->
*** one foot is equal to 12 inches ***
The disc is 27 inches .... so that means it is a little more than 2 feet (because 2 feet is equal to 24 inches)
27 inches minus 24 inches gets us 3 more inches ... so this means Eric's disc is 2 feet and 3 inches
I hope you understand this :D