Arc Length and Radians question- please help! Will mark brainliest! Is 20pts!

The answer is shown but please give me an explanation so I can show my work!

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?

Write as a product: ac^2–ad+c^3–cd–bc^2+bd