Answer:
The answer is 40°
Step-by-step explanation:
Solution
Now,
The Measure of major arc FD = 280°
Thus,
One complete angle measure 360°
Then
m∠FED = 360 - 180
m∠FED = 80°
Thus,
FE = DE ( the same circle Radius)
∠EFD = ∠EDF ( opposite angles to equal sides are equal)
Now
Applying angle sum property of a triangle in ΔEFD
∠EFD + ∠EDF + ∠FED = 180°
∠EFD + ∠EFD + 80 = 180
2∠EFD = 100
∠EFD = 50°
Hence, GF is tangent to the circle and the tangent always make right angles with the radius of the circle.
∠EFG = 90°
∠GFD + ∠EFD = 90°
∠GFD + 50 = 90
∠GFD = 40°
Therefore, The measure of the angle GFD is 40°
