Question

Angle G is a circumscribed angle of circle E. Major arc FD measures 280°.

Circle E is shown. Line segments F E and D E are radii. A line is drawn to connect points F and D. Tangents F G and D G intersect at point G outside of the circle. Major arc F D measures 280 degrees.

What is the measure of angle GFD?

40°
50°
80°
90°

Answer 1

40

Explanation:

Answer 2

The answer is 40°

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°