OG详解-OG10 数学2 Q4

Choice D is correct. The perimeter of a figure is equal to the sum of the measurements of the sides of the figure. It’s given that the rectangle has a length of 4 inches and a width of 9 inches. Since a rectangle has 4 sides, of which opposite sides are parallel and equal, it follows that the rectangle has two sides with a length of 4 inches and two sides with a width of 9 inches. Therefore, the perimeter of this rectangle is 4+4+9+9, or 26 inches.
Choice A is incorrect. This is the sum, in inches, of the length and the width of the rectangle. Choice B is incorrect. This is the sum, in inches, of the two lengths and the width of the rectangle. Choice C is incorrect. This is the sum, in inches, of the length and the two widths of the rectangle.