Whole plane consists of 360°
[tex]\\ \sf\longmapsto x+5+x+45+90+3x+6=360[/tex]
[tex]\\ \sf\longmapsto 5x+146=360[/tex]
[tex]\\ \sf\longmapsto 5x=360-146[/tex]
[tex]\\ \sf\longmapsto 5x=214[/tex]
[tex]\\ \sf\longmapsto x=214/5[/tex]
[tex]\\ \sf\longmapsto x\approx 43[/tex]
- m<DBE=3(43)+6=135
- m<ABF=90°
Somehow error present in diagram.(90° sign must not be x)
