let $a ,b ,c$ and $h_{a},h_{b},h_{c}$ be the length of the sides and the altitudes. let $D$ be the foot of the perpendicular from $A$ to $BC$. it easy to check that $DB=\frac{a^{2}+c^{2}-b^{2}}{2a}$ then $h_{a}^{2}=c^{2}-(\frac{a^{2}+c^{2}-b^{2}}{2a})^{2}=\frac{2a^{2}b^{2}+2a^{2}c^{2}+2c^{2}b^{2}-a^{4}-b^{4}-c^{4}}{{4a^{2}}}$ all the sides are integers then $2 | a^{4}+b^{4}+c^{4}$ but its impossible becuase: $a^{4}+b^{4}+c^{4}\equiv a+b+c=1995\equiv 1(mod2)$