Hi,
The sum of the measures of the internal angles of a polygon is 180(x-2), x being the number of its sides. In a pentagon, that sum is equal to 3(180°)=540°
So x= 540° - (110 + 107 + 108 + 131)° =84°
Your answer would be 84.
Hope this helps! If my answer was not clear enough or you’d like further explanation please let me know. Also, English is not my first language, so I’m sorry for any mistake.