Ta có: \(\widehat{E}-\widehat{F}=100^0\)
\(\Leftrightarrow\widehat{E}=100^0+\widehat{F}\)
Xét tứ giác EFGH có
\(\widehat{E}+\widehat{F}+\widehat{G}+\widehat{H}=360^0\)(định lí tổng các góc trong một tứ giác)
\(\Leftrightarrow\widehat{E}+\widehat{F}=360^0-50^0-110^0=200^0\)
\(\Leftrightarrow100^0+\widehat{F}+\widehat{F}=200^0\)
\(\Leftrightarrow2\cdot\widehat{F}=100^0\)
hay \(\widehat{F}=50^0\)
Ta có: \(\widehat{E}=100^0+\widehat{F}=100^0+50^0=150^0\)