Answer:
m∠EHG = 68
Explanation:
If the two ancient step pyramids are congruent,
ABCD ≅ EFGH
All the angles and sides of the two pyramids will be congruent.
By the property of congruence,
Base angles of both the pyramids will be congruent.
m∠ADC = m∠EHG = 68°
Therefore, m∠EHG = 68 will be the answer.