Answer: Congruent by AAS
Explanation:
FG and EH are congruent because they are given.
EH is perpendicular to EG because of the definition of perpendicular lines. Lines are perpendicular if they create right angles when they intersect.
FG is perpendicular to EG because of the definition of perpendicular lines. Lines are perpendicular if they create right angles when they intersect.
Angle G is congruent to Angle E because they are both right angles, and right angles are congruent.
Angle EIH and Angle FIG are congruent because of the vertical angles theorem.
Triangle EHI and Triangle GFI are congruent by the Angle-Angle-Side Theorem, or AAS.