rigid vs fixed

rigid and fixed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
rigid	No	Yes	No	No
fixed	No	Yes	No	No

As adjectives, rigid and fixed are synonyms defined as:

Other synonyms of rigid include set.

rigid (adjective)	fixed (adjective)
designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure	securely placed or fastened or set
incapable of or resistant to bending	(of a number) having a fixed and unchanging value
incapable of compromise or flexibility	fixed and unmoving
fixed and unmoving	incapable of being changed or moved or undone; e.g. "frozen prices"
incapable of adapting or changing to meet circumstances