Relax

Respuesta :

gmany
Look at the picture.
Use the Pythagorean theorem:
[tex]|DF|^2+11^2=(11\sqrt3)^2\\\\|DF|^2+121=121\cdot3\\\\|DF|^2+121=363\ \ \ |-121\\\\|DF|^2=242\to|DF|=\sqrt{242}\\\\|DF|\approx15.6\ inches.[/tex]

Ver imagen gmany