Question

circle f is congruent to circle j, and ∠efd ≅ ∠gjh. m∠dfe = 80°. what is the measure of arc gh?

Explanation:

Step1: Recall central - angle theorem

The measure of an arc is equal to the measure of its central - angle.

Step2: Use congruent - angle property

Since circle F is congruent to circle J and \(\angle EFD\cong\angle GJH\), and \(m\angle DFE = 80^{\circ}\), then \(m\angle GJH=80^{\circ}\).

Step3: Determine arc measure

The measure of arc \(\overset{\frown}{GH}\) is equal to the measure of its central - angle \(\angle GJH\). So \(m\overset{\frown}{GH}=80^{\circ}\).

Answer:

80