I'll help with the question at the bottom of the page. The rest are unfortunately too blurry.
The x is the adjacent side to the reference angle. The 7 is the hypotenuse. The hypotenuse is always opposite the 90 degree angle.
Let's use the trig ratio cosine.
cos(angle) = adjacent/hypotenuse
cos(39) = x/7
7*cos(39) = x
x = 7*cos(39)
x = 5.44002 which is approximate
x = 5.4
Make sure your calculator is in degree mode.
