Question

Don't understand the measure

Answer 1

Hello,


`\widehat{ABD}=(180-40)/(2)`=70 (sum of angles of a triangle=180°)


`\widehat{ABE}=180-70=110` supplementary angles


`\widehat{ABE}=\widehat{DCF}` translation BC


`\widehat{BCF}=110-40=70` image of the angle DAB by the axis symmetry DB


`\widehat{BCF}=\widehat{BEF}` opposed angles of a parallelogram
are supplementary.


`\widehat{BEF}=\widehat{HEG}` opposed angles by the vertex


`\widehat{HEG}=\widehat{IHE}=70` alterne-interne angles (sorry for the words English is difficult for me)