To solve for a missing value in a triangle, when would you use sine and when would you need the inverse sine? Please provide an example for each situation​

Me with this one question, and i'll upvote the brainliest answer

What is the distance between a and b? round your answer to the nearest tenth. a coordinate plane is shown. point a is located at negative 1, 5, and point b is located at 4, 1. a line segment connects the two points.

Kevin's bank offered him a 4.5% interest rate for his mortgage. if he purchases 3 points, what will be his new rate?