Question

The figure below shows a square ABCD and an equilateral triangle DPC.

Answer 1

Answer:

He assumes that triangle APB is an equilateral triangle.

Step-by-step explanation:

Answer 2

For the answer to the question above,
We can see that, DP = PC,  AD = BC and ∠ ADP = ∠ BCP = 30°  ( SAS postulate )
So the answer to the question above is the last one among the given choices which is Triangles APD and BPC are congruent SAS postulate.