In the straightedge and compass construction of the equilateral triangle below, which of the following reasons can you use to prove that ∠1 ≅ ∠2? Select all that apply. 
a. Angle-Side-Angle (ASA) 
b. Angle-Angle-Side (AAS) 
c. Side-Angle-Side (SAS) 
d. Side-Side-Side (SSS)