The missing statement in step 4 related to congruent angles in a geometric context is unclear without additional information or a diagram. While angle congruence often pertains to triangle congruence theorems, the available details are insufficient to provide a specific missing statement.
The missing statement in step 4, given the series of statements, is likely a conclusion or a result that follows from the angles being congruent. However, the provided information does not offer a clear path to identify the missing statement with certainty. Angle congruence typically leads to identifying congruent triangles or parallel lines, but the given information is insufficient to derive a specific geometric result. Moreover, it seems there might be some confusion, as the provided set of equations (1), (2), and (3) do not pertain to geometry but rather to Kirchhoff's rules in Physics, which deal with electrical circuits.
If we consider this a question about triangle congruence, we might infer the use of a theorem such as ASA (Angle-Side-Angle), SSS (Side-Side-Side), or AAS (Angle-Angle-Side) congruence could be employed to demonstrate that two triangles are congruent based on the given pairs of congruent angles. Nevertheless, without additional context or a diagram, it's impossible to provide the exact missing statement.
Completed Question:
What is the missing statement in step 4?
a) ∠ace ≅ ∠bcd
b) ∠eab ≅ ∠dbc
c) ∠eac ≅ ∠eac
d) ∠cbd ≅ ∠dbc