△ABC ~ △PQR. The areas of △ABC and △PQR are 64 cm2 and 81 cm2, respectively and AD and PT are the medians of △ABC and △PQR, respectively. If PT = 10.8 cm, then AD = ?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 9.6 cm
The ratio of the area of two similar triangles is directly proportional to the square of the median and the sides of the triangle.
⇒ ar(△ABC) : ar(△PQR) = AD2 : PT2
⇒ 64/81 = AD2/10.82
⇒ 8/9 = AD/10.8
⇒AD = 9.6 cm