Question

the width of a rectangle is 7 cm shorter than the length .if

Answer 1

题意：一个矩形的宽度比长度短了7厘米.如果矩形的周长是38厘米,得到

(a)宽度

(b)长度

(c)矩形区域

设length长=x,则width宽=x-7

perimeter周长=2（x+x-7）=38.

解之,得x=13

the width宽=the length长-7=13-7=6

(b) 由（a）知the length长=13

(c)the area of the rectangle 面积=the width长×the length宽＝13×6＝78