Worksheet for evaluating trigonometric functions with various problems and solutions.

Looking at Triangle ④, I can see it's a right triangle with the angle θ marked. The side labeled "Adj" is adjacent to angle θ, and the side labeled "Opp" is opposite to angle θ.

Since we have the Opposite side and the Adjacent side, we should use the TOA ratio, which stands for Tangent = Opposite/Adjacent.

Let me summarize my findings:

- Triangle ①: We have Opposite and Hypotenuse → SOH (Sine)
- Triangle ②: We have Adjacent and Hypotenuse → CAH (Cosine)
- Triangle ③: We have Opposite and Adjacent → TOA (Tangent)
- Triangle ④: We have Opposite and Adjacent → TOA (Tangent)

This matches the standard trigonometric ratios:
- SOH: Sine = Opposite/Hypotenuse
- CAH: Cosine = Adjacent/Hypotenuse
- TOA: Tangent = Opposite/Adjacent

The solution is:
Triangle ①: SOH
Triangle ②: CAH
Triangle ③: TOA
Triangle ④: TOA