What is answer of my question

Given : Side of square (a) = 12 cm We know that diagonal of square (d) = \sqrt{2} a = 12 \sqrt{2} So perimeter of the required triangle is = 12 cm + 12 cm + 12 \sqrt{2} cm = 24 cm + 12 \sqrt{2} cm = 12 (2 + \sqrt{2}) cm