Question

Determine the measure of ∠DFB.

1)

67°

2)

136°

3)

69°

4)

68°

Answer 1

Explanation:

The arc defining one part of the circle + the arc vertically opposite the given arc when added must be divided by 2. That's the value of angle at the intersection.

In this case, (arc BD + arcEC)/2 = < EFC

Arc bd = 69

Arc CE = 67

<EFC = (69 + 67)/2 = 68

So the answer is number 4