**C. 1305.** A spiral is made out of a square of side \(\displaystyle n\) units, as shown in the *figure*, by always breaking the line 1 unit before reaching the already existing part of the spiral. Similarly, a spiral is made out of a regular triangle of side \(\displaystyle 1.8n\) units by breaking the line 1.8 units before closing up. (The diagram shows the two spirals for the case of \(\displaystyle n = 4\).) For what value of n will the lengths of the two spirals be equal?

(5 points)

**Deadline expired on 12 October 2015.**