Question

ABC is a triangle with D as midpoint of AB. DE is perpendicular to AC and DF is perpendicular to BC. also DE is equal to DF. prove that triangle ABC is an isosceles triangle

Answer 1

as in isosceles triangle one side is not equal to the other two side as per the question one side EF is not equal to the other of DF and DE .it proves that ABC is an isosceles triangle