Which mnemonic correctly encodes sine = opposite/hypotenuse, cosine = adjacent/hypotenuse, and tangent = opposite/adjacent?

In a right triangle, an angle θ has opposite side length 7 and hypotenuse length 25. What is sin(θ)?

Using a calculator in degree mode, compute θ = arctan(3/4). Round θ to the nearest tenth of a degree.

In a 30°-60°-90° triangle the long leg has length 1. Find the short leg and the hypotenuse, simplifying and rationalizing where appropriate.

Evaluate tan(2π/15) to the nearest tenth. (You must set the calculator mode appropriately before evaluating.)