Answer:
75°
Step-by-step explanation:
While it may appear that QRS is a straight line, it is not so since m∠QRS = 179° and if it was a straight line, it would be 180°
The figure actually represents three rays with endpoint at R
The three rays are RQ, RS and RG
Draw another ray RT with endpoint at R and opposite to ray RG. Opposite rays have angles that add up to 180°
Therefore m∠GRT = 180°
m∠SRT = m∠QRG since they are opposite angles
Since m∠QRG = 105°, therefore m∠SRT = 105°
m∠GRS + m∠SRT=180° since these angles are formed by two opposite rays
Substituting we get
m∠GRS + 105 = 180
m∠GRS = 180-105 = 75°
