1, take a square origami, the color and size are not limited, you need to cut it first.
2. Fold the paper in half, fold it into a crease and fold it along the crease.
3. Fold the four corners of origami in half and be symmetrical.
4. Open the four corners folded in step 3 and fold inward, as shown in the figure below. Open them all.
5. Unfold the crease and turn the origami over.
6. Fold in half along the original center line, and then fold back to the front.
7. Open the two ends separately and make a square.
8. Press all the creases hard. Well, paperphone can fold.
As early as the eighteenth century, the word "telephone" was used in Europe to refer to microphones strung together with wires (cups strung together with wires) The telephone was attributed to Alexander Graham Bell. The principle of early telephone is that sound is a compound vibration in the air, which can be transmitted to solids and to conductive metals through electric pulses. Bell applied for the telephone patent in March 1876.
The improvements and inventions of telephone in history include: toner microphone, manual switchboard, dial, automatic telephone exchange, program-controlled telephone exchange, dual-tone multi-frequency dialing, voice digital sampling and so on. In recent years, new technologies include ISDN, DSL, VoIP, analog mobile phone and digital mobile phone.