∠EOM+∠MOF=90
∠FON+∠MOF=90
∠EOM+∠MOF=∠FON+∠MOF=90
所以,∠EOM=∠FON
2)延长EO到G
∠FON+∠MOF=90
∠FON+∠NOG=90
∠FON+∠MOF=∠FON+∠NOG=90
所以,∠MOF=∠NOG
∠EON+∠MOF=∠EON+∠NOG=180
即有,∠EON+∠MOF=180
∠EOM+∠MOF=90
∠FON+∠MOF=90
∠EOM+∠MOF=∠FON+∠MOF=90
所以,∠EOM=∠FON
2)延长EO到G
∠FON+∠MOF=90
∠FON+∠NOG=90
∠FON+∠MOF=∠FON+∠NOG=90
所以,∠MOF=∠NOG
∠EON+∠MOF=∠EON+∠NOG=180
即有,∠EON+∠MOF=180