Respuesta :

A. Is your answer But i think ion know
mjankiewicz
Pythagoras's theorem

[tex]y^2+6^2=|MN|^2[/tex] , y > 0

[tex]y^2+36=(9+3)^2 \\\\ y^2+36=144 \\\\ y^2=144 - 36 \\\\ y^2=108 \\\\ y=\sqrt{108}=\sqrt{36 \times 3} \\\\ y=6\sqrt3[/tex]