电视机有21英寸、25英寸、29英寸等规格，一般的说法都是说屏幕对角线的猜蔽尺寸或者是指电视有效画面对角线的长度，但是这种说法经我们自己测量以后是不宽兆差准确的，慎皮行业内所说的CRT电视机的屏幕大小其实是玻屏（我们正面所能看到的电视机玻璃屏幕）的模具配合线的对角线尺寸；模具配合线简称MM线；在制造玻屏时，玻屏制造模具分为低模和凸模，在制造过程中这两种模具相结合则会出现模具配合线，通过模具配合线的对角线测量得到准确的电视机尺寸，所以我们自己单单的去拿尺子丈量电视机屏幕所得出的结果是不准确的。
26寸的液晶电视的禅腊屏幕尺寸（以4:3为比例计算）是长52.832cm，宽39.624cm
28寸的液晶电视的屏幕尺寸（以4:3为比例计算）是长56.896cm，贺皮滑宽42.672cm
32寸的液晶电握弊视的屏幕尺寸（以4:3为比例计算）是长65.024cm，宽48.768cm
计算公式：
a的平方+b的平方等于你要算的那几个数的平方（比如26的平方）
一般都是4：3的
就是a：b＝4：3
单位是英寸
1英寸大约等于2.45cm
自己算吧
对角线长度兄历神一样，长宽比不一样，面积是不一样的，羡亏最简单的例子，假设对角线为5，长宽为4和3，面积烂贺是12，如果是正方形，也就是长宽比是1：1，，面积是12.5。
History
The first CRT televisions had circular pictures. Their size was logically measured by diameter. Later, the circular picture was masked off with a rectangle whose corners touched the edge of the circle, so the diameter measurement turned into a corner-to-corner diagonal measurement.
Simplicity
A diagonal measurement allows the size of the screen to be communicated with a single figure instead of having to think about two. Because most screens have the same or similar ratio of width to height, this conveys the same information.
Tradition
The diagonal measurement has now been grandfathered in. People have an idea of what an 18 inch screen is. If you saw 10.8 inches by 14.2 inches, you would have to stop and think about it.
是屏幕对角线的长度。