Respuesta :

Answer:

DEC+DEF=180

DEC=180-116

DEC=64°

in triangle DCE

angle D+angle C+angle E=180

7y+6+4y+64=180

11y+70=180

11y=180-70

11y=110

y=110/11

y=10°

angle C=4y

=4(10)

=40°