The answer is 3.785, but rounding it to the nearest hundredth is 3.78 or 3.79, depending on rather they wanted you to take the 5 and round up or just leave it off.
The length of the shadow is 124.7 in
<u>Explanation:</u>
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Given:
Angle, θ = 30°
Height of the fence, h = 72 in
Length of the shadow, l = ?
Given:
tan 30° = 

Therefore, the length of the shadow is 124.7 in
The equation of a circle is: (x - h)² + (y - k)² = radius² where (h, k) is the center. Now just plug in your given information and simplify.
(x - 2)² + (y - 0)² = 9²
Your equation is:
(x - 2)² + y² = 81