How to calculate the unfolding size of a box

How to calculate the unfolding size of a box

09:47 August 2 CRT display size refers to the diagonal size of the picture tube. The maximum visible area is the maximum range of graphics that the display can display. The size of the picture tube is usually measured by the length of the diagonal, in inches (1 inch = 2.54cm), The common display areas are 15 inches, 17 inches, 19 inches, 20 inches and so on. The display area is smaller than the size of the display tube. The display area is expressed by the product of length and height, and it is usually expressed by the diagonal length of the visible part of the screen. The visual range of the 15 inch display is about 13.8 inches, and that of the 17 inch display is mostly between 15 and 16 inches, The visual area of the 19 inch monitor is about 18 inches
The size of LCD display refers to the diagonal size of LCD panel, in inches (1 inch = 2.54cm), now the mainstream has 15 inches, 17 inches, 19 inches and so on