A rectangle is four times as long as it is wide.if the area of the rectangle is 1600cm,waht are its dimensions
一个长方形的长是宽的4倍,长方形的面积是1600cm²,长、宽各为多少?
Solution:
Let x be the width of the rectangle
So,x × 4x = 1600,4x² = 1600,x² = 400,x = square root of 400 = 20 cm.
The length = 20×4 = 80 cm
So,the dimensions are 80cm × 20cm.
平方 = square of .,to the power of 2
开平方 = square root of .,root .
开立方 = cubic root of .