△ABC is such that AB=3 cm, BC=2 cm and CA=2.5 cm. △DEF is similar to △ABC. If EF=4 cm, then the perimeter of △DEF is
15 cm
Since, the triangles are similar,
ABDE=ACDF=BCEF=24=12
⇒DE=2AB=2×3=6 cm, and DF=2AC=2×2.5=5 cm
∴ Perimeter of △DEF=(DE+EF+DF)=6+4+5=15 cm.