trigonometry

apersonwithaquestion:

if there is a right triangle with the hypotenuse being 5 units and the long leg being 4 uits, what would the formula be to find angle x between the ypotenuse and the shorter leg?

5^2=4^2+x^2
5^2-4^2=x^2
x=sqrt(5^2-4^2)
x=sqrt(25-16)
x=sqrt(9)
x=3 (shorter leg length)

cos( alpha ) = x/hypotenuse
alpha = acos( x/hypotenuse )
alpha = acos( 3/5 )
[input]acos( 3/5 )[/input]