First, we need to compute the area of the inner circle
Area of a circle is computed as follows:
Substituting with D = 12 ft:
Next, we need to calculate the area of the outer circle (its diameter is 3 + 12 + 3 = 18 ft), as follows:
Finally, the approximate area of the track is 254.5 ft² - 113.1 ft² = 141.4 ft²