Square root of 64 over 25

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books

What is the output, or dependent variable of quantity? 1: x 2: f(x) 3: y