Question

SAT数学题求翻译解答

A rectangular rug covers half of a rectangular floor that is 9 feet wide and 12 feet long. If the dimensions of the rug are in the same ratio as those of the floor, how many feet long is the rug?
A 6 B 21/2 C 2根号7 D 6根号2 E 4根号6
答案是D求翻译解答

Answer 1

一长方形地毯正好可以覆盖半块长12英尺宽9英尺的长方形的地面，如果地毯的长与宽的比例与地面相同，那么地毯长是多少？

首先，由地毯面积是地面面积一半知地毯面积是54，然后由于长与宽比例为4:3，所以长为6根号2，选D。

追问

为什么长与宽比例为4:3，长就为6根号2？