Answer:
85 (D.)
Explanation:
The sum of all the degrees in a quadrilateral is 360, and since a triangle is half of a quadrilateral, the sum of the degrees in a triangle is 180.
With the given information, we can create the equation:
40+55+x=180
Simplifying on the left side gives us:
95+x=180
Subtracting 95 from both sides gives us:
x=85
Therefore, the solution to your problem is 85.
Hope this helped!