right angle

American  

noun

right angles plural

1. the angle formed by two radii of a circle that are drawn to the extremities of an arc equal to one quarter of the circle; the angle formed by two perpendicular lines that intersect; an angle of 90°.

---

right angle British  

noun

1. the angle between two radii of a circle that cut off on the circumference an arc equal in length to one quarter of the circumference; an angle of 90° or π/2 radians

2. perpendicular or perpendicularly

---

right angle Scientific  

/ rīt /

1. An angle having a measure of 90°.

---

right angle Cultural  

1. An angle measuring ninety degrees, formed by the intersection of two perpendicular lines. (Compare acute angle and obtuse angle.)

---

Other Word Forms

Derived Forms

• right-angled
  adjective

Inflected Forms

Nouns

• right angles
  plural

Etymology

Origin of right angle

Middle English word dating back to 1350–1400

Example Sentences

See Examples For:

right angle

Will the robots in his specially built factory ever line up at precisely the right angle?

From The Wall Street Journal ● May 17, 2026

It occurs when an electric current flows through a material while a magnetic field is applied at a right angle.

From Science Daily ● Mar. 1, 2026

Water must be flowing, skies must be clear and the setting sun must hit at the right angle.

From Los Angeles Times ● Feb. 12, 2026

But it also has an amazing property: If two lines on the Earth’s surface meet at a right angle in reality, they will still do so on the map.

From Slate ● Jan. 21, 2026

It should have stood at a clean right angle to the main tower, but it was angled strangely, as if it had been hastily built.

From "The Rock and the River" by Kekla Magoon