In rectangle READ

Given, ∠ROE = 60

According to given figure, ∠AOE = 120, ∠AOD = 60 and ∠ROD = 120.

⟹In triangle AOE, consider ∠EAR = ∠DEA = x

∠AOE + ∠EAR + ∠DEA = 180

x + x + 120 = 180

2x + 120 = 180

2x = 60

x = 30, i.e. ∠EAR = 30

⟹In triangle AOD, consider ∠RAD, = ∠EDA = y

∠RAD + ∠EAR + ∠AOD = 180

y + y + 60 = 180

2y = 120

y = 60, i.e.∠RAD = 60.