The Total solution for NCERT class 6-12
BE and CF are two equal altitudes of atriangle ABC. Using RHS congruence rule, prove that the triangle ABC isisosceles.
In ╬ФBEC and ╬ФCFB,
тИаBEC = тИаCFB (Each 90┬░)
BC = CB (Common)
BE = CF (Given)
тИ┤ ╬ФBEC тЙЕ ╬ФCFB (By RHS congruency)
тЗТ тИаBCE = тИаCBF (By CPCT)
тИ┤ AB = AC (Sides opposite to equal angles of a triangle areequal)
Hence, ╬ФABC is isosceles.