Gauge Chart Implementation

Question

I am trying to implement a Gauge Chart that ranges from 0 to 100 and when the value is over 80 it is green, and less than 80 it is red.

1. Insert "Text Area".
2. What HTML code should I write?
3. What JavaScript code should I write?
4. How should I make the value a calculated column?

Thank you so much¡.

Francisco

Be able to make the graph I need.