Question 82019
(1/2)(arcAC - arcAC) = angB

(1/2)(220 - 140) = angB

(1/2)(80) = angB

40 = angB

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(1/2)(arcDE - arcDF) = angB

(1/2)(200 - arcDF) = 40

200 - arcDF = 80

- arcDF = -120

arcDF = 120