Answer:
109°
Explanation:
The sum of the interior angles of a pentagon is 540 degrees,
take off from 540 the sum of the knows angles
540 - (121 + 108 + 102 + 100) =
540 - 431 =
109°
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check
109 + 121 + 108 + 102 + 100 =
540°
the answer is good