The picture is a bit difficult to see, but I think angle hmg = 15°
Shell use 13 cups of oatmeal
The second option shows AA symmetry.
The angles of a triangle have to add up to 180. When adding the given angles, you will find that the missing angle is equal to what is given in the other triangle.
An example is how in the second option’s triangle, the two given number add up to 91. 89 is needed to make it equal 180 and 89 is in the same position is the first triangle.