Proportion Resize

[telco]

Hello everyone how can i resize the window that kepts the aspect ratio?

i have found this link below but i cannot know how to implement it..

https://forums.indigorose.com/forum/...345#post218345

can anyone help me? my window size is 1366x768 and when i resize i would like that it will always keep in ratio.

thanks

[telco]

Height/3 = Width/4
Height/3 = 2000/4
Multiply Both sides by three to isolate the Height.
Height = (2000/4)*3
Height = (500)*3
Height = 1500

Test the result.
1500/3 = 2000/4;
500=500;

That code is share by @Centauri Soldier
but i dont know how implement on the my current page to make it proportion everytime i scale/resize the window.