Marker, colored paper, A4 paper.
1. Fold the long side to the middle with green rectangular colored paper for about 1 cm, then fold the short side of one side for 1 cm, and stick it with double-sided adhesive tape along the folded side.
2. Then tear off the double-sided adhesive film, and stick the short sides together, and stick the long sides together along different diagonal lines to form a three-dimensional tetrahedron.
3. Then draw eyes and mouth with black mark, blush with red mark, and finally stick a cut red bow above your eyes.