Answer: 140 degrees
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Explanation:
See the diagram below.
We start with triangle PQR with the given angles mentioned. Then you extend out segment QR to form line QR. It goes off infinitely in both directions.
The exterior angle x adds to the interior angle Q = 40 to get 180
x+40 = 180
x+40-40 = 180-40 ... subtract 40 from both sides
x = 140
The exterior angle is 140 degrees
