In a circular garden of radius 7 m with centre O, two points A and B lie on the boundary such that the length of the minor arc AB is 11 m. (Take π=722.)
a. Find the measure of ∠AOB in degrees.
b. Calculate the area of the sector AOB in square metres.
c. What percentage of the total area of the garden does the sector AOB represent? Give your answer correct to one decimal place.