Question

If ΔABC ~ ΔQRP, ar (ΔABC) / ar (ΔPQR) =9/4 , AB = 18 cm and BC = 15 cm, then Pris equal to

(A) 10 cm (B) 12 cm (C) 20/3 cm (D) 8 cm

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Answer 1

Answer:

We know that the ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding sides.

ar (ΔABC) / ar (ΔPQR) = BC2/RP2

9/4 = (15)2/RP2

RP2 = (4/9) ×225

PR2 = 100

Therefore, PR = 10 cm