Mathematics

Problem

In a circle of radius

r

cm, two sectors subtend central angles of 30° and 50° respectively. a. (i) Explain why the ratio of the areas of the two sectors is

30:50

. b. (ii) If the area of the

30^{\circ}

sector is 77 cm

^{2}

, find the value of

r

. c. (iii) Hence determine the area of the

50^{\circ}

sector. Take

\pi = \dfrac{22}{7}