Question

In quadrilateral ACBD, AC = AD and AB bisects ∠ A (see figure). Show that ∆ABC ≅ ∆ABD. What can you say about BC and BD?

Answer 1

Answer:

In △ABC and △ABD,

AC=AD (Given)

∠CAB=∠DAB (AB bisects ∠A)

AB=AB (Common)

∴△ABC≅△ABD (By SAS congruence rule)

∴BC=BD (By CPCT)

∴, BC and BD are of equal lengths.