Question:
The perimeters of two similar triangles are 25 cm and 15 cm respectively. If one side of first triangle is 9 cm, what is the corresponding side of the other triangle?
Solution:
It is given that perimeter of two similar triangle are $25 \mathrm{~cm}$ and $15 \mathrm{~cm}$ and one side $9 \mathrm{~cm}$.
We have to find the other side.
Let the corresponding side of the other triangle be x cm.
Since ratio of perimeter $=$ ratio of corresponding side
25 cm15 cm=9 cmx
$25 \mathrm{~cm} \times x=9 \mathrm{~cm} \times 15 \mathrm{~cm}$
$x=\frac{135 \mathrm{~cm}}{25 \mathrm{~cm}}$
$x=5.4 \mathrm{~cm}$
Hence $x=5.4 \mathrm{~cm}$