1999 Gauss 8 Problem 18

The equilateral triangle has sides of 2x and x+15 as shown. The perimeter of the triangle is

\textbf{(A)}\ 15\quad \textbf{(B)}\ 30\quad \textbf{(C)}\ 90\quad \textbf{(D)}\ 45\quad \textbf{(E)}\ 60

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Gauss contests here.