Question

D, e, f are midpoint of sides bc, ca, and ab of triangle abc. if perimeter of triangle abc is 12.8 cm, then find perimeter of triangle def?

Answer 1

I think you will satisfy with this answer.

Answer 2

DF || BC and 2DF = BC {mid-point theorem}

similarly EF || AB and 2EF = AB and DE || AC and 2DE = AC

DFBC=EFAB=DEAC=12DFBC=EFAB=DEAC=12

=>ABC EFD=>ABC EFD

=>Ar.EFDAr.ABC=(EFAB)2=>Ar.EFDAr.ABC=(EFAB)2

let the area of DEF be x cm2cm2

=>x20=(12)2=>x20=(12)2