From the figure, we have ∠ A ≅ ∠P = 40°
⇒ = and ∠A ≅ ∠P
SAS similarity theorem states that two triangles are similar if two sides in one triangle are in the same proportion to the corresponding sides in the other, and the included angles are equal.
Therefore, ΔABC ∼ ΔPQR by SAS similarity theorem.
Correct Answer is : SAS similarity theorem