Respuesta :

Look at the figure

  • AB=BC=AC

∆ABC is an equilateral triangle

Using angle sum property

[tex]\\ \sf\longmapsto <ABC=180/3=60°[/tex]

#2

Equivalent sides have similar adjacent angles

  • Let <DCE=<DEF=x

[tex]\\ \sf\longmapsto x+x+50=180[/tex]

[tex]\\ \sf\longmapsto 2x+50=180[/tex]

[tex]\\ \sf\longmapsto 2x=130[/tex]

[tex]\\ \sf\longmapsto x=65[/tex]