Respuesta :

Answer:

∠IGH = 57º

Step-by-step explanation:

The supplement to 99º is 180 - 99 = 81º

The vertical angle to 42º is 42 º

together they are two angles of ∆ GHI

81 + 42 = 123

The remaining angle of the triangle is ∠IGH

∠IGH = 180 - 123

∠IGH = 57º

∠IGH = 57º     is the remaining answer