On the hour, what is the acute and obtuse angle formed by the hour and minute hands?

On the hour, the hour and minute hands form an acute angle of 1, 2, 10 and 11 o'clock.

The hour and minute hands form obtuse angles at 4 o'clock, 5 o'clock, 7 o'clock, and 8 o'clock.

The hour time is characterized by the fact that the minute hand always points to the 12 position.

An acute angle should be formed at the hour, that is, the angle between the clamps is greater than 0° and less than 90°;

An obtuse angle should be formed at the hour of the hour, that is, the angle clamped is greater than 90° and less than 180°, and the angle of the hour hand and the minute hand at the hour hour is in order:

1 point: 30°; 2 o'clock: 60°; 3 o'clock: 90°; 4 o'clock: 120°; 5 o'clock: 150°; 6 o'clock: 180°;

7 o'clock: 150°; 8 o'clock: 120°; 9 o'clock: 90°; 10 o'clock: 60°; 11 o'clock: 30°; 12 o'clock: 0°

Based on the above known data and conditions, it can be known that:

On the hour, the hour and minute hands form an acute angle of 1, 2, 10 and 11 o'clock.

The hour and minute hands form obtuse angles at 4 o'clock, 5 o'clock, 7 o'clock, and 8 o'clock.

125 °, every minute after a minute of sensitivity, the angle of the needle is: 360 (12 * 60) =, six ten is filial piety is really deviated from six points 10 *, a total of 120 + 5 = 125 °, hehe.

According to the rough rock analysis of the question stem, it can be obtained: 30° 3=90°, so at 9 o'clock, the angle of the trouser composed of the hour hand and the minute hand on the clock face is an angle of 90°, which is a right angle

Therefore, in front of the stool B.

At 3 o'clock, the hour and minute hands form (90) degrees or (270) degrees, and at 3:20 a.m., the acute angle of the hour and minute hands is (20) degrees.

20 degrees.

At 7 o'clock, 360-30 7 = 360-210 = 150 degrees.

The empty spike to: 7 o'clock, when the small angle between the needle and the minute hand is (150).

At 5 o'clock, the angle of the hour hand and the minute hand on the clock face is: 30° 5=150°, which is an obtuse angle;

So the answer is:

Answer: Mu Chi Chong case]: b

From 3:00 to 3:19, the minute hand travels 6. ×l9=114。, the hour hand goes 0 5.

19=9．5。At 3 o'clock, the angle between the hour hand and the minute hand is 90. , so the angle at 3:19 is 114.

90。-9．5。=14．5。。Swift annihilation.

On a 12-hour clock, the angle formed between the hour and minute hands can be divided into four different cases: obtuse angle, straight overhead angle, acute angle, and flat angle. These angles depend on the specific time of the clock.

1.Obtuse angle (180° Angle < 360°): Between approximately 7 and 11 o'clock, the angle between the hour and minute hands is greater than 180 degrees, creating an obtuse angle.

For example, between 8 and 9 o'clock, the angle between the hour and minute hands is about 225 degrees.

2.Right angle (angle = 90°): Between about 3 o'clock and 9 o'clock, the angle between the hour and minute hands will be 90 degrees, forming a right angle. For example, at 3 o'clock and 9 o'clock on the hour, the angle between the hour and minute hands is 90 degrees.

3.Acute angle (0° "Angle < 90°): Between about 1 o'clock and 5 o'clock, the angle between the hour and minute hands will be less than 90 degrees, creating an acute angle. For example, between 2 and 3 o'clock, the angle between the hour and minute hands is about 60 degrees.

4.Flat angle (angle = 180°): At 12 o'clock on the hour, the angle between the hour and minute hands will be 180 degrees, forming a flat angle.

These angles are approximate estimates, and the actual angles depend on the precise time of the clock. The scale of the clock may also affect the accuracy of the angle.

At 1:20, the hour hand has passed a third of an hour, that is, a third of the time between 1 o'clock and 2 o'clock, and the angle between each adjacent two hours is 30 degrees, so the angle of the hour hand relative to 12 o'clock is 30 + 10 = 40 degrees.

If the minute hand has traveled 20 minutes, the angle between it and 12 o'clock is 120 degrees.

120-40 = 80 degrees.

A: The angle between the hour and minute hands is 80 degrees.