BE & CF r 2 equal altitudes of a triangle ABC using RHS proove that triangle ABC is isosceles

In triangles BEC and CFB,we have

BE=CF.... given

angle BEC= angle CFB... each is 90 degrees

CB=CB .. common

so the triangles are cong by RHS rule

so

 angel BCE= angle CBF.. CPCT

 i.e. as far as triangle ABC is concerned,

 angle B= angle C

So ABC is an isoceles triangle.