Answer:
m∠CGF=25°
Explanation:
we know that
In a circle, a radius that bisects a chord is perpendicular to the chord
so
CS is perpendicular to AC
The triangle GFC is a right triangle
Remember that the sum of the measures of the interior angles in a triangle must be equal to 180 degrees
m∠CGF+m∠GFC+m∠GCF=180°
we have
m∠GFC=90°
m∠GCF=65°
substitute
m∠CGF+90°+65°=180°
m∠CGF+155°=180°
m∠CGF=180°-155°
m∠CGF=25°