This week, Mr. Chen led us to learn the preliminary understanding of diagonal, and let me know that there are various angles in life, obtuse, right and acute.

Our bright red scarf is composed of two acute angles and an obtuse angle; The five-star red flag consists of four right angles; At 3 o'clock, the angle formed by the hour hand and the minute hand is a right angle; At 8:55, the hour hand and the minute hand form an acute angle. ...

There are many corners in life. Did you find them carefully?