Answer: 120.
Step-by-step explanation: the angles of a triangle add up to 180 degrees. angles c and d are given and their values add up to 120 degrees. so E must be 180-120, which equals 60 degrees. We also know that a straight line is 180 degrees and since one side is 60 degrees, the other one must add up with 60 to give 180, which is 120.
