Answer:
The measure of Arc EH is 123°.
Explanation:
Consider the diagram below.
It is provided that ∠EDH ≅ ∠EDG.
This implies that: ∠EDH = ∠EDG
The arc measure is same as the measure of the central angle.
That is:
arc FE = ∠EDF = 57°
arc FG = ∠FDG = 66°
Compute the measure of angle ∠EDH as follows:
arc EH = ∠EDH
=∠EDG
= ∠EDF + ∠FDG
= 57° + 66°
= 123°
Thus, the measure of Arc EH is 123°.