241. An angle of the triangle is $60^{\circ}$. Find the sides of the triangle, knowing that they are expressed as integers.
241. Denoting the sides forming the angle $60^{\circ}$ by $x$ and $y$, and the third side by $z$, we get the equation:

$$
x^{2}-x y+y^{2}=z^{2}
$$

Solving by one of the previous methods, we get:

$$
\begin{gathered}
x=\left(m^{2}-n^{2}\right) t, y=m(m-2 n) t, z=\left(m^{2}-m n+n^{2}\right) t \\
x=\frac{m^{2}-n^{2}}{\Delta}, y=\frac{m(m-2 n)}{\Delta}, \quad z=\frac{m^{2}-m n+n^{2}}{\Delta} .
\end{gathered}
$$

We obtain an infinite number of similar triangles.