x = 109
this is pentagon
the sum of the interior angles of a polygon is
sum = 180°( n - 2) where n is the number of sides.
sum = 180° × 3 = 540° thus
x + 121+ 108 + 102 + 100 = 540
x + 431 = 540
subtract 431 from both sides
x = 540 - 431 = 109
