ABCD is a quadrilateral in which AB = BC and AD = CD. Show that BD bisects both the angles ABC and ADC.
Given: ABCD is a quadrilateral in which AB = BC and AD = CD
To prove :- ADB =BDC
and ABD = DBC
Proof : In ABD and CBD
AB = CD (Given)
BD = BD (common)
AB = BC (given)
ABD CBD (SSS congruency)
ABD = CBD (by CPCT)
And ADB = BDC (by CPCT)
Therefore, BD bisects both the angle ABC and ADC.
Hence proved