The formula for the volume of a cylinder is v= 3.14r^2h. A cylinder has a volume of 300x feet ^3 and a radius of 5 feet

Height = 3.82

Step-by-step explanation:

(3.14)(5)²

(3.14)(25)

= 78.5

300 = 78.5h

300/78.5 = 78.5h/78.5

h = 3.821656051 or approximately 3.82

Given that sin A=0.725 is an acute angle in a right angled triangle we are required to find cos A
sin A=opposite/hypotenuse
sin A=0.725=29/40
this implies that
opposite=29
hypotenuse=40
using the Pythagorean theorem we can calculate the adjacent hence the cosine function
c^2=a^2+b^2
thus
40^2=29^2+b^2
b^2=40^2-29^2
b^2=759
b=sqrt759
b=27.54995436~27.55
hence 
cos A=27.55/40=0.68875