Answer:
[tex]\sqrt{44} = 2\sqrt{11}[/tex]
Step-by-step explanation:
Apply pythagorean theorem:
ABD is a right triangle with angle ADB = 90
hence AD = [tex]\sqrt{AB^{2} - BD^{2} }[/tex] where BD = 10 because it is half of BC
AD = [tex]\sqrt{12^{2}-10^{2} }[/tex] = [tex]\sqrt{44} = 2\sqrt{11}[/tex]
