6. Determine the perimeter of the similar triangles

If $\triangle ABC \sim \triangle PQR$, $BC =$ 21 $cm$ and $QR =$ 37 $cm$ and perimeter of $\triangle PQR =$ 92 $cm$, then the perimeter of $\triangle ABC$ is  $cm$.

 

(Note: If the answer is a whole number, write as it is. If not, round off the number to $2$ decimal places.)