Tools/materials: scissors, tape, ruler, white paper, plastic paper. Get the tools ready first. Draw a trapezoid with an upper length of 1cm, a lower height of 3.5cm and a lower length of 6cm. Cut out the trapezoid with scissors. Using paper trapezoid as template, cut out four plastic plates. Glue these four pieces together to make a pyramid without horns. Download the film source for holographic projection on the internet with your mobile phone.
Put the pyramid upside down on the mobile phone, and the mobile phone will play the film source to get the final effect. Find a transparent plastic plate or a transparent empty bottle, the beverage bottle I use here, and cut it in the middle with a knife or scissors. Leave a part near the bottle mouth, and then cut it again with scissors near the bottle mouth. After cutting, scrape the newly cut edge with a knife to avoid scratching your hand.
Divide the cut funnel-shaped transparent part into four parts, and then fold it along the selected corner line for extrusion. After all four corners are extruded, press the back with scissors again to keep the shape unchanged. Press the four sides.
Then put the smaller side of the table in the middle of the material played by our mobile phone (you can find holographic video material by searching on a certain sound). If the mesa is uneven or larger than the middle part of the video, it can be repaired with a knife. Finally, turn off the lights, play the video in a dark environment and watch the 3D holographic effect.