Aregular 24 sided polygon is rotated with its center of rotation at its center what is the smallest degree of rotation needed to map the polygon back

In the figure below, segment ac is congruent to segment ab: which statement is used to prove that angle abd is congruent to angle acd? a.)triangle acd is similar to triangle abd. b.)triangle acd is congruent to triangle abd. c.)segment a.d. is congruent to segment ac. d.)segment a.d. is congruent to segment dc.