# Equilateral Triangles using Matchsticks

You are given an equilateral triangle of three matchsticks like given figure. What is the minimum number of sticks needed to add three more equilateral triangles to it?

**Answer :** 3

**
Explanation :** Technically 4 triangles require 12 matchsticks, but we only have 6, that means each matchstick must be used in 2 triangles. So every triangle has to border 3 other triangles (one on each side).It’s a tetrahedron (a three-sided pyramid).

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