Equilateral Triangles

题目

Equilateral Triangles
You are using a drawing program on a computer.You place several equilateral triangles of the same size on the screen.You observe that you can cover any of these triangles by moving the other triangles without rotating.
What is the minimum number of triangles you have to place on the screen to ensure that this observation holds true for every case?

答案

等边三角形
你正在电脑上使用一个画图程序,屏幕上放一些相同大小的正三角形,你发现任意一个三角形都能通过移动（而不旋转）别的三角形将它遮住.
求使上述命题始终正确时,屏幕上至少放放几个三角形?