Answer: 43
To find the sum of the value of all interior angles of a polygon, we must use the formula [tex]( n-2)180[/tex], n being the number of sides in the polygon. Since this quadrilateral has for sides, we replace n with 4.
[tex](4-2)180[/tex] evaluates to 360, so we can assume that the sum of all interior angles is 360 degrees, including the ones that they have given us. The sum of the measure of all other angles (25°+155°+137°) is 317°, and the remaining measurement to get to a total of 360 is ∠x. To evaluate the measure of angle x, we subtract 317 from 360 to get 343.
