How can the area of this triangle be determined by forming a rectangle?

Select from the drop-down menus to correctly complete the statements.

Copy and rotate the triangle and place it next to the existing triangle to form a rectangle. The length of the rectangle is
Choose... 2 4 9 18
units. The width of the rectangle is
Choose... 2 4 9 18
units. The area of the rectangle is
Choose... 9 18 22 36
square units.

The area of the triangle is half the area of the rectangle, so the area of the triangle is
Choose... 9 18 22 36
square units.