Let triangle \( A B C \) have altitudes \( h_{a^{\prime}}, h_{b^{\prime}}, h_{c} \) from points \( A, B, C \) respectively. If \( h_{a}=8, h_{b}=8, h_{c}= \) 10. The perimeter of the triangle formed by joining feet of altitudes of \( \triangle A B C \) is
(1) \( \frac{32 \sqrt{2}}{25} \)
(2) \( \frac{16 \sqrt{21}}{5} \)
(3) \( \frac{16 \sqrt{21}}{25} \)
(4) \( \frac{8 \sqrt{21}}{5} \)
