Question

The perpendicular bisector of side AB of ∆ABC intersects side BC at point D. Find AB if the perimeter of ∆ABC is with 12 cm larger than the perimeter of ∆ACD.

Answer 1

AB+BC+AC-12=AC+CD+AD
AB+BC-12=CD+AD
AB+BD+CD-12=CD+AD=BD
AB+BD-12=0
AB=12cm