Respuesta :

Answer:

BAE + ECB + ABC = 180 [ BEING INTERIOR TRIANGLE ANGLES SUM ]

Answer:

180 = Angle ABC + BAE + ECB

180 = Angle ABC + 27 + 21

Angle ABC = 180 -27 -21

Angle ABC = 132

Angle ABC = Angle ADC (opposite angles of a parallelogram are equal).

Angle = 132

Step-by-step explanation: