en.wikipedia.org/wiki/Right_angle

A rectangle is a quadrilateral with four **right angles**. A square has four **right**
**angles**, in addition to equal-length sides.

www.mathopenref.com/angleright.html

Definition of an **right angle** (one whose measure is exactly 90 degrees).

www.mathsisfun.com/rightangle.html

Note the special symbol like a box in the angle. If we see this, it is a **right angle**.
The 90° is rarely written in. If we see the box in the corner, we are being told it is ...

www.mathsisfun.com/definitions/right-angle.html

**Math** explained in easy language, plus puzzles, games, quizzes, worksheets and
... **Right Angle** ... An angle which is equal to 90°, one quarter of a full revolution.

www.khanacademy.org/math/basic-geo/basic-geo-angle/basic-geo-angle-types/v/acute-right-and-obtuse-angles

the radian is the standard unit of angular measure, used in many areas of
**mathematics**. An **angle's** measurement in radians is numerically equal to the
length of ...

study.com/academy/lesson/what-is-a-right-angle-definition-formula-quiz.html

In this lesson, you will learn about the properties that identify **right angles**. ... Amy
has a master's degree in secondary education and has taught **math** at a public ...

www.splashmath.com/math-vocabulary/geometry/right-angle

Definition of **Right Angle** explained with illustrated examples. Also, practice lots of
**math** problems with fun **math** worksheets at Splash **Math**.

mathforum.org/library/drmath/view/58420.html

Date: 06/01/99 at 22:13:07 From: greg Subject: **Geometry** What is a left angle? I
know it is not a **right angle** and is not 90 degrees. Our **math** teacher will give us a
...

thinkmath.edc.org/resource/shape-right-angle

Meaning. Informal: an **angle** that matches the corner of a (rectangular) piece of
paper, or the **angle** at the base of a capital L or the top of a capital T. These are
all ...