Question 2: The area of a big square is the square of the length of the hypotenuse of a triangle, that is,10 *10+6 * 6 =136.
The area of the small square is 136 minus the area of four small triangles, and 4 * 10 * 6/2 = 120, so the area of the small square is136-120 =16.
The third question: subtract the triangle area from the rectangular area, and you can get the result: assuming that the length and width are XY respectively,
XY = 80°
80-0.5X * Y/2+0.5X * 0.5Y/2+0.5Y 80.5 x/2 = 80-5/8XY = 30