Hello,
17/4π rad = (4π+π/4 )rad
17/4 π mod 2π = π/4 (rad) or 45°
Not sure when this is from but if it was recent and you still need the answer I believe it’s 1/5.
I think they are not similar because the angles are different
Trumpet=1\2 x 4=2
trombone=2+2=4
tubas=2
answer=2+2+4=8