AB=6
Step-by-step explanation
Step 1
set the equations
due to lengths AD and DC are the same, and the distance DB is common for triangels ADB and DBC
we can state that
triiangles are similar,so
and
Step 2
solve for AB
a) replace the AB value from equation(1) into equation(2)
therefore, the answer is
AB=6
I hope this helps you