Solve the Problem $45 \mathrm{~cm}$ the Triangle Is Isosceles Now, but If Its Base

Multiple Choice

Solve the problem.
-The perimeter of a triangle is $45 \mathrm{~cm}$ . The triangle is isosceles now, but if its base were lengthened by $3 \mathrm{~cm}$ and each leg were shortened by $3 \mathrm{~cm}$ , it would be equilateral. Find the base of the original triangle.

A) $14 \mathrm{~cm}$
B) $11 \mathrm{~cm}$
C) $10 \mathrm{~cm}$
D) $17 \mathrm{~cm}$