98 points one geometry questioni'm supposed to be graduating ! find the volume of each figure. round your answers to the nearest hundredth, if necessary

remark 
Somewhere you need to find the area of the pentagon. It's the base. I'm not sure what the height is (8 or 8.3) 8.3 is for certain, but then I don't know what the 8 is. 

Formulas
V  = Bh
Area of B = (1/4) sqrt(5(5 + 2sqrt(5)  ) * a^2

Sub and solve
Find the base first
a = 12 miles
Area of B = 0.25 * sqrt(25 + 10sqrt(5) ) * 12^2
B = 0.25 sqrt(25 + 10*3.1623) * 144
B = 0.25 sqrt(25 + 31.623) * 144
B = 0.25 sqrt( 56.623) * 144
B = 0.25 * 7.5248 * 144
B = 270.893

Find the Volume
V = B * h
V = 270.893 * 8.3
V = 2248.4   <<<<<<<<< Answer

I will put an alternate answer in the comment section