How to solve these problems ?

The center of a circle represent by the equation (x+9)^2+(y-6)^2=10^2 (-9,6), (-6,9), (6,-9) ,(9,-6)

As a salesperson you get $50/day and $3.60/each sales you make.if you want to make $60 in one day, how many sales would you need need to make ? a 3b 4c 5d 6 show work.

When you find the area of a triangle do you use in. or in2