List the angles of the triangle in order from smallest to largest measure.

For any right triangle, the 90 degree angle is always the largest. The longest side of a triangle is always opposite the largest angle. Similarly, the shortest side of a triangle is always opposite the smallest angle.

Angle G is opposite side HI = 4 which is the smallest side, so angle G is the smallest angle.

Angle H is the middle angle as this is the longer leg, but it is not longer than the hypotenuse. The hypotenuse is always the longest side.