Answer:
Step-by-step explanation:
Area of sector = angle/360 * pi * r^2
7.1 = 40/360 * 22/7 * r^2
7.1 = 1/9 * 22/7 * r^2
63.9 = 22r^2/7
r^2 = (7 * 63.9)/22
r^2 = 20.331818181818
r = square root of 20.331818181818
r = 4.51
d = r * 2 = 4.51 * 2 = 9.02