Whats the opposite of a circle​

u a letter cuz dats a shape

i think a square because a circle is round and a square is not!

where is the diagram

frederick the great and the war of austrian succession. frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. he also declared himself king of bohemia, and maria theresa sent troops to retake bohemia. in august he led 80,000 of these men across the frontier into bohemia, his