how to change toshiba estudio 452 paper size ( see attachment)

[alamin]

Can anyone please tell me how can i change standard paper size of this menu from LT format to AB format ? Is there any regional issue ? if yes then how can i change it ?
thanks in advanced.WhatsApp Image 2020-12-04 at 9.12.29 AM.jpgWhatsApp Image 2020-12-04 at 9.12.29 AM.jpg