CalcuLaTeX | pretty printing calculator language with support for units | Math library

In my reactJS app, I've function that calls a helper function to get some calculation's result. Here is my component;

I have two classes one called Userinterface and the other a Canvas I need the user to be able to enter the values of a velocity, angle, and time to be able to render fireworks onto the Canvas. However when I use the button to fire what grabs the values of the JTextFields, the Canvas won't repaint(). Nothing will happen no matter what value I enter I defined the x and y in another class but the getters and setters won't produce any value.

Why isn't my shape drawn on the Canvase when I call repaint()?

I am working coordinates system as shown below:

x and y are in meters. I am interested in only positive x,y. I want to convert (x,y) to (lat,lon) and vise versa.

I thought it is simple and I dont see a problem with my solutions below. But I am not getting very correct results.

My Solution:

As we see in the image below, I considered the Latitude and Longitude as angles of 2 circles:

1. (x,y) to (lat,lon)

I applied the Arc Length formula (here), shown below, on both; x and y

Hence, my functions are: