The diagram shows a regular pentagon

a) 540 b) 108

Step-by-step explanation:

to find the interiour angle of any shape subttract the number of side by 2 and then times by 180    180 (n-2)

and then 2 find one angle divide total by number of sides  180 (n-2) /n

if tht makes sense

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)