D, e and f are respectively the mid points of sides bc ,ca and ab of an equilateral triangle . △abc. prove that △def is also an equilateral triangle

See proof below

Step-by-step explanation:

Consider triangle with midpoints D, E, F of the sides BC, AC and AB, respectively.  If D, E and F are midpoints  of the sides BC, AC and AB, then

Triangle ABC is equilateral triangle, then

If AB=BC=AC, then EA=CE=FA=BF=DC=DB.

By SAS theorem, ΔFAE≅ΔDCE≅ΔEBD.

Congruent triangles have congruent corresponding sides, then

EF=FD=DE. This means that triangle DEF is equilateral.

step-by-step explanation: