Find the volume of the cone & round to two decimal places. : )

Remark
The 68° will get you 1/2 the base if you use the right trig function.
After that, all you need do is use the Cone Formula for Volume.

Step One
Find 1/2 the base.
The height and 1/2 the base are in a right triangle. Put into more formal language 
Tan(68°) = Opposite side / Adjacent Side 

Givens
Angle = 68°
Opposite Side = 4.2 feet.

Substitute
Adjacent side = opposite Side / Tan(68°)
Adjacent side = 4.2 / Tan(68°)
Adjacent side = 1.697 feet

Step Two
Find the Volume

Formula
V = 1/3 pi r^2 h

Givens
V = ???
pi = 3.14
r = 1.6969
h = 4.2 feet.

Solve
V = 1/3 3.14 * 1.6969^2 * 4.2
V = 12.66 cubic feet.

Heya !

Check the attachment.
Hope it helps you :)