Answer:
11.31
Step-by-step explanation:
The diameter of the circle is 3.6 units.
Value of "a"
Circumference of a circle in terms of radius:
Circumference = 2 · π · r = 2 · 3.14 · 1.8 = 11.31 (*)
In terms of diameter:
Circumference = π · d = 3.14 · 3.6 = 11.3 (*)
In terms of area:
Circumference C = √4·π·A = √4·π·10.18 = 11.31 (*)