It would help you with starting by drawing a picture first and labeling it with the info you've been given in the problem. After you draw your picture, you look at what you need to find which would've been X in my picture.
So, looking at angle we were given, the other known information we have is the distance of 6.5ft from the wall to the bottom of the ladder which is the ground.
The ground is adjacent to the angle of 74°.
The side X is opposite of the angle of 74°.
Which means you need to choose the trig ratio that has adjacent and opposite in it.
A way to remember is (SOHCAOHTOA)
Sin = Opposite / Hypotenuse
Cos = Adjacent / Hypotenuse
Tan = Opposite / Adjacent
The rhyme we use is "Some Old Hippy Caught Another Old Hippy Tripping On Acid"
Tan would be the trig ratio you need to use to find the answer to your problem so you'd set it up...
Tangent of 74 = X / 6.5
Then you'd multiply both sides by 6.5 and get...
6.5 ・Tan(74) = X
We use use graphing calculators for these. I'm not sure if you do too but if so...
Make sure you go to [Mode] on your calculator and change it from Radian to Degree.
Then simply type in the equation...
6.5 ・ Tan(74) =
And you'll get
22.68819388
Then round to whatever place you're supposed to and you're done.