1. Remove the upper pyramid part and cut the remaining into quarters.
2. Choose three identical parts and cut each of them into halves.
3. Divide the 6 pieces into 2 groups based on the thickness of thier triangle-shaped edges.
"Thicker group: Long-distant boomerang"
"Thinner group: Short-distant boomerang"
4. Cut each piece along the dotted lines shown in the diagram.
5. Hook 3 pieces together as shown in the diagram, and secure it with tape. Fold all the triangle edges upward and it's done.
6. Hold it vertically and just snap it.
A paper carton