Cot^2 x-csc^2 x=-1 for all values of x

In the coordinate plan (-6,9) b (3,9) c (3,3) def is shown in the coordinate plan below

What is the square root of 45? (step by step working plz)

Brady has a 20 year fixed rate mortgage for $215,500 with monthly payments of 1,305.89.the annual interest rate is 4%. what is the total cost of the principal and interest for this loan rounded to the nearest dollar