It is helpful to become familiar with the rules for secants of a circle.
The product of the numbers on the same chord is the same.
.. 2*x = 5*8
.. x = 20
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The picture is not drawn to scale. (They almost never are.)
I hope this helps, sorry for my messy handwriting. If you have any questions feel free to ask me!
You know from the definitions of trig functions that
.. tan(42°) = (height of courthouse above measuring device)/(distance to courthouse)
.. (height of courthouse above measuring device) = tan(42°)*(305 ft) ≈ 274.6 ft
Since the measuring device is 5 ft high, the height of the courthouse is approximately 280 ft. (selection C)
