Answer:
6. 21.0°
7. 39.6°
8. 58.0°
9. 72.9°
Step-by-step explanation:
6. Reference angle (θ) = x°
Hypotenuse = 15
Adjacent = 14
Apply CAH:

Plug in the values


x ≈ 21.0° (nearest tenth)
7. Reference angle (θ) = x°
Opposite = 19
Adjacent = 23
Apply TOA:

Plug in the values


x ≈ 39.6° (nearest tenth)
8. Reference angle (θ) = x°
Hypotenuse = 17
Adjacent = 9
Apply CAH:

Plug in the values


x ≈ 58.0° (nearest tenth)
9. Reference angle (θ) = x°
Opposite = 43
Hypotenuse = 45
Apply SOH:

Plug in the values


x ≈ 72.9° (nearest tenth)