A plan for an observation deck is shown below. The design consists of a major sector ABCOA ABCOA\,ABCOA of a circle with centre OOO, joined to a triangular viewing platform AODAODAOD. It is given that:
Find:

the size of angle AODAODAOD, in radians, to 3 decimal places,
the length of arc ABCABCABC, in metres, to one decimal place,
the total area of the deck, in m2\text{m}^2m2, to one decimal place.
19 exam-style questions on Edexcel A Level Maths 5.3 Areas of Sectors and Segments. Each one has a worked solution and a mark scheme showing where the marks go.