Show that each diagonal of a rhombus bisects the angle through which it passes :
In rhombus ABCD, AC is its diagonal we have to prove that AC bisects ∠A and ∠C.
A Now, in ΔABC and ΔADC
AC = AC (Common)
AB = CD (Sides of a rhombus)
BC=AD
∴ΔABC≅ΔADC (SSS condition)
∴∠BAC=∠DACand∠BCA=∠DCA (c.p.c.t.)
Hence AC bisects the angle A.
Similarly, by joining BD, we can prove that BD bisects ∠B and ∠D.
Hence each diagonal of a rhombus bisects the angle through which it passes.