问题
单项选择题
The shaded region in the figure above represents a rectangular frame with length 18 inches and width 15 inches. The frame encloses a rectangular picture that has the same area as the frame itself. If the length and width of the picture have the same ratio as the length and width of the frame, what is the length of the picture, in-inches ？（）
A.A
B.B
C.C
D.D
E.E
答案
参考答案：A
解析：
设照片的长为a，宽为b，则根据题意可得：
(1)2ab=18×15
(2)[*]
由以上方程组可解得该照片的长为a=[*]英寸。