Respuesta :

Answer:

45 cm

Step-by-step explanation:

Since the two triangles are congruent to each other, their sides will also be equal to each other.

So, sides of triangle LMN = sides of triangle FGE

Perimeter of triangle FGE = 9 + 15 + 21

                                      = 45 cm

So, perimeter of triangle LMN will also be 45 cm

Hope you understood!!