1. The problem statement, all variables and given/known data A triangle with a hypotenuse of 13.5 and height of 11.8. Find the measure of angle P. Angle p is on the same line as the 90 degree angle and I found out that it must be sine. 2. Relevant equations sine = opposite/hypotenuse 3. The attempt at a solution sin p = 11.8/13.5 sin p = .874 Textbooks answer: sin p = 71.468 It says I need to use something called 2nd sine like this: 2nd sin(11.8/13.5), which I can't find on my calculator and hasn't been introduced in the textbook until now. It doesn't explain 2nd sin. What does it mean and how do I go about solving this on my own?