Read the list of words. circular circus circumnavigate circumference circumstance Based on the shared root, what is the common subject for all the words? circles navigation geometry shapes

Shouldn’t you be able to answer all these if you actually read?

Allusion and illusion. an allusion is an indirect reference, whereas an illusion is something that is unreal or incorrect. each of the nouns has a related verb form: allude “to refer indirectly to,” and illude (not a very common word), which may mean “to delude or deceive” or “to subject to an illusion.”