The diagram shows a sector OAB of a circle, centre O and radius r cm. The length of the arc AB is p cm and angle AOB is Ѳ radian.

(a) Find Ѳ in terms of p & r.

(b) Deduce that the area of the sector is 1/2pr cm^2.

Given that r = 4.7 and p = 5.3, where each has been measured to 1 decimal place, find, giving your answer to 3 decimal places:

(c) The least possible value of the area of a sector.

(d) The range of possible values of Ѳ.

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I don’t understand this question properly. What is the least possible value? And what is the range?

By taking given r & p's value,

A = ½ * (4.7)^2 * (5.3/4.7) [Using A = 1/2 * r^2 * Ѳ]

= 12.455 cm^2

But book’s answer: 12.206 cm^2.