Can anyone suggest a yt video/ playlist which explains the concept for such graphical questions

There is a direct formula for this type of question. If the inequality is in the form a|x| + b|y| <= c, the total area is simply 2c^2 / (ab). This formula works even if the center is shifted, such as in a|x - 1| + b|y - 1| <= c, because the shape is a rhombus. For this specific question, since there is a constraint that y >= 2, the required region will be exactly half of the total area.

It was covered in taksh I remember, dont know about YT, but u can try searching 'graphing regions of inequalities involving modulus (absolute value) in coordinate geometry'