Question : The perimeters of two similar triangles are 25 cm and 15 cm respectively. If one side of the first triangle is 9 cm, then the corresponding side of second triangle is . . .
(a) 5.4 cm
(b) 5.3 cm
(c) 5.2 cm
(d) 5.1 cm
Doubt by Aditi
Solution :
Using Perimeter of similar Triangle Theorem
According to this theorem, the ratio of the perimeters of two similar triangles is the same as the ratio of their corresponding sides.
Perimeter of first triangle / Perimeter of second triangle = Side of first triangle / corresponding side of second triangle.
Let the corresponding side of second triangle be x.
ATQ
25/15 = 9/x
25x=15×9
25x=135
x=135/25
x=5.4 cm
Hence, a) 5.4 cm would be the correct option.