Length (cm) x width (cm) =144x81. The inch of the TV generally refers to the diagonal length of the TV screen, according to the conversion of 1 inch =2.54 cm, the diagonal length of the 65-inch TV screen is 65x2.54=165.1 cm. The LCD display ratio is 16:9, so the width is 16*8.992=143.9cm, the height is 9*8.992=80.93cm. 1, avoid watching TV for a long time, so that the nervous system and the body produce fatigue, affecting the healthy development of physical and mental, affecting the normal conduct of other activities such as learning. 2, avoid too close to the eye in the screen issued by the strong light for a long time under stimulation, not only easily reduce the visual acuity and adaptability, and easily cause the reduction of ciliary muscle adjustment function, the lens gradually convex, resulting in myopia. 3, avoid the volume is too high for a long time under the stimulation of high volume, not only easily reduce the sensitivity of hearing, the formation of bad hearing habits, and easily lead to the decline of visual and other sensitivity.