As P is equidistant from the sides, P is the in center of the triangle.
r is the in radius of the triangle, viz. 4(√2 - 1) cm
Let the sides of the triangle be a, a, a √2
As Δ=1/2 (a)(a) = r(s),
a2/2 = 4(√2-1)(a+a+a√2)/2
⇒ a = 4√2
Area = 1/2(a2) = 16 sq.units