Question Number 11373 by ketto last updated on 22/Mar/17
Answered by sm3l2996 last updated on 22/Mar/17
$$\overset{−} {\mathrm{D}}\overset{\rightarrow} {\mathrm{F}}=\mathrm{D}\overset{\rightarrow} {\mathrm{A}}+\mathrm{A}\overset{\rightarrow} {\mathrm{B}}+\mathrm{B}\overset{\rightarrow} {\mathrm{F}} \\ $$$$\mathrm{DF}=\sqrt{\mathrm{DA}^{\mathrm{2}} +\mathrm{AB}^{\mathrm{2}} +\mathrm{BF}^{\mathrm{2}} } \\ $$$$\mathrm{DF}=\sqrt{\mathrm{8}^{\mathrm{2}} +\mathrm{10}^{\mathrm{2}} +\mathrm{6}^{\mathrm{2}} }=\sqrt{\mathrm{200}} \\ $$$$\mathrm{DF}=\mathrm{10}\sqrt{\mathrm{2}} \\ $$
Commented by sm3l2996 last updated on 22/Mar/17
$$\mathrm{DF}=\mathrm{10}\sqrt{\mathrm{2}}\mathrm{cm} \\ $$