So the white area =192-141= 51.

So T+S=5 1.

In the isosceles right triangle ABC, BC= 12, and the height on BC = 12/2=6 (because it is an isosceles right angle, the two shadow triangles next to it are also isosceles right angles), so S=36.

Then T=5 1-36= 15.

T= length x width, length = 16-6= 10.

So the width = 1.5.