PLS help

Solve:

Greg buys 40 yards of wire fence to create
a triangular pen for his dog. One side of
the pen will use 19 yards of fencing. The
other two sides will be equal in length.
Greg would like his pen to use exactly
40 yards of fencing so that he doesn't
have any left over. What is the length of
each of the other two sides of the pen?​