Question

What is m∠CDJ? Im not sure what it is

Answer 1

The 'x' and 'y' axes are perpendicular.
So angle ADJ is 90 degrees.

So (4x) + (3x-8) = 90 degrees.

Solve that and you'll know what 'x' is.

Then angle CDJ is just (3x-8).

I'm sure you can handle it from here.

Answer 2

`4x+3x-8=90\\ 7x=98\\x=14\\\\ \angle CDJ=3\cdot14-8=34^(\circ)`