Question

Triangle ABC is such that AB=3cm,bc=2cm&CA=2.5cm.If triangle DEF is similiar to triangle ABC and EF=4cm,then perimeter of triangle DEF is

Answer 1

permeter of triangle ABC =  perimeter of triangle DEF
perimeter of triangle ABC= sum of all sides
                                        = 3 +2+2.5
                                         7.5 cm
therefore, perimeter of triangle DEF = 7.5 cm

Answer 2

Answer:

15

Step-by-step explanation:

In ΔABC

AB = 3 cm

BC = 2 cm

AC = 2.5 cm

Perimeter of triangle = Sum of all sides = 3+2+2.5 = 7.5 cm

Triangle DEF is similar to triangle ABC

Corresponding side of EF in triangle ABC is BC = 2cm

Theorem :The ratio of the sides of similar triangle is equal to the ratio of the perimeter of corresponding triangles

So, Let the perimeter of triangle DEF be x

So, $\frac{4}{2} =\frac{x}{7.5}$

$\frac{4 \times 7.5}{2} =x$

$15=x$

Hence perimeter of triangle DEF is 15