9514 1404 393
Answer:
ΔA₁CA ~ ΔBCB₁
Step-by-step explanation:
The triangles share angle C. The 30° angles are also congruent, so the triangles are similar by the AA theorem.
It is convenient to name the similar triangles by matching the similar angles. Here, angle A₁ matches the acute angle at B, and (of course) angle C matches itself. So, we can name the triangles using those two angles in that order.
ΔA₁CA ~ ΔBCB₁
