Question

凌晨 $4:20$ 时，钟表两根指针形成的锐角是多少度？

What is the measure of the acute angle formed by the hands of a clock at $4:20$ a.m.?

$0^{\circ}$

$5^{\circ}$

$8^{\circ}$

$10^{\circ}$

$12^{\circ}$

知识点：时钟

在 $4 : 20$ ，时针位于 $4$ 和 $5$ 之间 $\frac{1}{3}$ 的位置。

每个小时刻度代表 $360 \div 12 = 30^{\circ}$ 。所以时针从 $4$ 之后又移动了 $30 \div 3 = 10^{\circ}$ 。

注意 $20$ 分钟时，分针指向 $4$ 。因此形成的角为 $10^{\circ}$ 。

所以正确答案是 D。

At $4 : 20,$ the hour hand will be a $\frac{1}{3}$ of the way between $4$ and $5.$

Each hour represents $360 \div 12 = 30^{\circ}.$ This means the hour hand will be $30 \div 3 = 10^{\circ}$ past $4.$

Note that at $20$ minutes, the minute hand will be at $4.$ This means the degree formed is $10^{\circ}.$

Thus, D is the correct answer.