How to use sine,cosine,tangent to determine side X in the triangle below Step 1) Based on your givens and unknowns, determine which sohcahtoa ratio to use Since we know the 67 angle, its adjacent side length and we want to know length of the opposite side, we should use tangent Step 2) Set up an equation based on the ratio you chose in the step 1 $ tan(67) = \frac{opposite}{adjacent} $ $ tan(67) = \frac{x}{14} $ (Let's Step 3) Cross multiply and solve the equation for the side length.
