Question

许多电视屏幕是长方形，并用对角线长度来标记尺寸。标准电视屏幕的水平长度与高度之比为 $4 : 3$ 。一台“二十七英寸”电视的水平长度最接近下列多少英寸？

Many television screens are rectangles that are measured by the length of their diagonals. The ratio of the horizontal length to the height in a standard television screen is $4 : 3.$ The horizontal length of a "27-inch" television screen is closest, in inches, to which of the following?

$20$

$20.5$

$21$

$21.5$

$22$

答案：D

知识点：勾股数比与比例

难度评级：1000

解答：

因为长高比为 $4:3$ ，长、高、对角线组成 $4:3:5$ 的直角三角形。对角线长为 $27$ ，所以水平长度为最接近 $21.5$ 。 $\dfrac{4}{5}(27)=21.6,$

所以正确答案是 D。

Since the length and height are in ratio $4:3,$ the length, height, and diagonal form a $4:3:5$ right triangle. The diagonal is $27,$ so the horizontal length is $\dfrac{4}{5}(27)=21.6,$ which is closest to $21.5.$

Thus, the correct answer is D.

2003 AMC 10B 第 6 题

答案：D

难度评级：1000

解答：

其他年份的第 6 题