I'm not entirely sure, but if the measure of both A and D are 55, then the answer for F would be 35. The angles didn't grow, but the sides of the two triangles did. Both of them still have 90 degree angles, and if angles A and D have 55, then angle F would match angle C and the answer would be 35. In a triangle, the angles will always add up to 180, so 90 plus 55 is 145 and so the last angle would have to be 35.
