THE UNIT SQUARE IS DIVIDED INTO A 9-SQUARE GRID (FIG. 1). FOUR LIN...

28. - DE THI TOAN QUOC TE KANGAROO NAM 2016 LOP 9 10 CO DAP AN DE TIENG ANH
DE THI TOAN QUOC TE KANGAROO NAM 2016 LOP 9 10 CO DAP AN DE TIENG ANH

28. The unit square is divided into a 9-square grid (fig. 1). Four line segments are drawn (fig. 2).

What is the area of the shaded square?

(A) 1 3 (B) 2 5 (C) 3√2 10 (D) √3 4 (E) 4 9