Answer:
21 inch
Explanation:
It means that the length of the diagonal of the TV is 20 inch or 25 inch.
Width of TV = 28 inch
diagonal of TV = 35 inch
Let L be the length of the TV
Use Pythagorean theorem
Diagonal^2 = length^2 + width^2
35^2 = L^2 + 28^2
L^2 = 1225 - 784
L^2 = 441
L = 21 inch