Firstly, notice the relationship the two triangles have. They have conjoining ends that form vertical angles (looks like a middle x). Vertical angles are equivalent in measure of degrees.
Secondly, notice that the triangle on the right side is a right triangle. One of its angle's measurements are also given; 40 degrees. If you know that the sum of a triangle's angles equal 180 degrees, then simply subtract the known angles measurements from 180.
180-(90+40)= 180-130=50.
Therefore, the vertical angles measurement is equivalent to 50 degrees.
Apply the principle of the sum of all angles in a triangle equivalent to 180 degrees to the left triangle, and you will be able to find the measurement of the "?" angle.
180-(50+25)= 180-75=105
SO HERE IS YOUR ANSWER= 105 degrees is the value of the angle marked with a "?"
