3 Answers:
A. angle KLJ
B. angle MLK
D. angle EFH
All three angles mentioned have a tiny square marker to visually show the reader that the angle is a right angle, aka 90 degree angle. We can say that the segments forming the angle are perpendicular segments.
For angle GFE, it is smaller than angle EFH because point G is between or inside the angle EFH. So there is no way that angle GFE is a right angle.
