Peanuts by Charles Schulz for September 23, 1980
Transcript:
Sally and Charlie Brown sit at the table. Sally writes mathematical signs.<BR><BR> Sally holds up her paper and says, "Not bad, eh? This little sign means 'congruent to.'"<BR><BR> Sally continues to write "congruent to" signs.<BR><BR> Sally turns to Charlie Brown and says, "If you ever need a 'congruent to,' I can whip one out in nothing flat!"<BR><BR>
This is in my math textbook!