
We have,
ΔABC ~ ΔPQR
Area (ΔABC) = 81 cm2,
Area (ΔPQR) = 49 cm2
And AD and PS are the altitudes
By area of similar triangle theorem

Since, the ratio of the area of two similar triangles is equal to the ratio of the squares of the squares of their corresponding altitudes and is also equal to the squares of their corresponding medians.
Hence, ratio of altitudes = Ratio of medians = 9 : 7