Question

In circle C, mDE = 84°. Find each measure.

1. measure of angle EFD​

Answer 1

Answer: 42 degrees

Reason:

Use the inscribed angle theorem. Central angle DCE subtends the arc DE, so angle DCE = 84 degrees. Inscribed angle EFD is also subtending this same arc (DE), meaning we cut the arc/central angle measure in half to get 84/2 = 42.