1 and A4 paper have specifications of 2 1cm× 29.7cm, so the side length which is 7 inches shorter than A4 paper is about 2.3cm.
2. The specific size of 2.phone 4 is11.5cm x 5.86cm x 0.93cm, so 7 inches is basically equivalent to the length of two Phone4s.
Commonly used unit
1, km.
Kilometer, also known as kilometer, is a unit of length, abbreviated as "km", which is usually used to measure the distance between two places. Its common conversion relationship: 1 km (km) = 1 0,000m (m) = 1 00,000m (cm) =10,000mm (mm); 1.6 1 km = 1 mile? .
2, meters.
The unit of length "meter" in the international system of units originated in France. 1790 in may, a special Committee composed of French scientists suggested that one fortieth of the total length of the earth meridian passing through Paris should be used as the unit of length.
3. decimeter.
Decimeter or dm is one of the metric units of length, and 1 decimeter is equivalent to one tenth of 1 meter. The common conversion relationship is as follows: 1 decimeter = 0.000 1 kilometer (km) = 0. 1 meter (m) = 10 centimeter (cm) = 100 millimeter (mm).
4. centimeters.
Centimeter, unit of length; Chinese: centimeter (s), abbreviated as cm. The unit conversion of centimeters is as follows:1cm =10 mm = 0.1decimeter = 0.0 1 m = 0.0000 1 km? [3]。
Five, um.
Millimeter, also known as millimeter (or millimeter), is a unit of length and rainfall, and the symbol is ㎜. 1mm is equivalent to one thousandth of 1mm (this means "milli"). The decimal relation is as follows:1mm = 0.1cm = 0.01decimeter = 0.001m = 0.000001km.
6. micron.
Micron is a unit of length, and the symbol (micron) is pronounced as (miú). 1 micron is equivalent to one millionth of 1 meter (which means "micro").
Baidu encyclopedia-length unit