Given the incomplete proof below, what is the missing reason for the statement in step 4? Given: ZABC - ZABD and AB is the
angle bisector of CAD
Prove: AC AD
B
D
Given
1. ZĀBC = ABD
2. ZCABZDAB
3. ABAB
4. A ABC ZA ABD
Given and definition of angle bisector
Reflexive property of congruence

A. AAS
B. SAS
C. ASA
D. CPCTC

Why is the huronian supergroup rock formation particularly interesting to scientists? because it looks like a cross-section of a giant, stone encyclopedia because it formed during the period when oxygen began to accumulate in the atmosphere because it contains unusually large amounts of oxygen and sulfur because it dramatically altered the planet's development when it first formed