Question : The perimeter of two similar triangles $\Delta \mathrm{ABC}$ and $\Delta\mathrm{ PQR}$ are $60\;\mathrm{cm}$ and $36\;\mathrm{cm}$ respectively. If $\mathrm{PQ} = 18\;\mathrm{ cm}$, then $\mathrm{AB}$ is:

Question : The areas of two similar triangles $\Delta ABC$ and $\Delta PQR$ are 36 sq. cm and 9 sq. cm, respectively. If $PQ$ = 4 cm, then what is the length of $AB$ (in cm)?

Question : $\Delta ABC$ and $\Delta DEF$ are two similar triangles and the perimeters of $\Delta ABC$ and $\Delta DEF$ are 90 cm and 54 cm respectively. If the length of DE = 36 cm, then the length of AB is: 

Question : If $\triangle ABC \sim \triangle PQR$, AB =4 cm, PQ=6 cm, QR=9 cm and RP =12 cm, then find the perimeter of $\triangle$ ABC.

Question : In a triangle ${ABC}, {AB}={AC}$ and the perimeter of $\triangle {ABC}$ is $8(2+\sqrt{2}) $ cm. If the length of ${BC}$ is $\sqrt{2}$ times the length of ${AB}$, then find the area of $\triangle {ABC}$.