'equal-angled' originates from modern English compounding of the adjective 'equal' and the past-participial adjective 'angled'. 'equal' ultimately comes from Latin 'aequalis', where 'aequ-' meant 'equal'. 'angled' is derived from the noun 'angle', which comes from Old French 'angle' and Latin 'angulus', where 'angul-' meant 'corner'.

'equal' entered English via Old French and Middle English from Latin 'aequalis'; 'angle' came from Latin 'angulus' through Old French 'angle' into Middle English. The compound form 'equal-angled' is formed in Modern English by combining these elements to describe shapes with equal angles.

Initially, the components referred separately to 'equal' and to 'angle' (corner); combined as 'equal-angled' the term has meant 'having equal angles' since its formation and has retained that geometric sense.