Cosine is [tex]\frac{hypotenuse}{adjacent}[/tex].
Apply the equation:
[tex]sin(t) = \frac{3}{5} \\3^2 + b^2 = 5^2\\b^2 = 5^2 - 3^2\\\\\sqrt{b^2} = \sqrt{5^2}- \sqrt{3^2}\\\\\\b = 5 - 3 \\\\b = 2[/tex]
B is the adjacent side so
cosine is:
Cos(t) = 5/2
Have a great day,
And I hope this helps you!
