Chapter 9.3, Problem 8WE

To determine

The time when the hands of the clock forms $120°$ .

Answer to Problem 8WE

At 8 o’ clock and 4 o’ clock.

Explanation of Solution

Given information:

The angle formed between the hands of the clock is $120°$ .

A clock is a circle made of 360 degrees, and that each number represents an angle and the separation between them is 360/12=30 degree.

In $120°$ separation between the numbers is $120°÷30°=4$

So at 8 o’clock and 4 o’clock minute hand is on 12 and the hour hand is on 8 and 4 respectively.

Therefore at 8 o’clock and 4 o’clock angle will $120°$