Here’s a fun fact I just learned!
It’s fairly well known nowadays that lemmings do not, in fact, follow one another off cliffs to their deaths. The myth has been persistent for many years, and was notably perpetuated by Disney in their documentary White Wilderness, which showed lemmings apparently diving from a cliff to their deaths. Truly though, these lemmings had been flown half way across the world and were thrown from the cliffs by the documentary’s producers.
A pizza is larger than two of another just before it hits 1.5 times the radius (sqrt 2 times, to be exact, about 1.41). So if the radius is 1.5 times bigger, like in the OP, you always know it’s more than twice the area.