直角

1. Origins, structure, and basic meaning

• Structure: 直角 is read as ちょっかく and means “right angle”.
• Basic usage: The examples show an angle drawn with a ruler and a board corner checked for squareness.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is a 90-degree angle, larger than acute 鋭角 and smaller than obtuse 鈍角.