Transcript right angle

Types of Angles
Angles form when rays share the same
endpoint.
This common endpoint is called the vertex.
The two sides are rays of the angle.
ray
ray
vertex
A Matter of Degrees
Angles are measured in degrees. There are 90
degrees (90°) in a square corner like the one
shown here.
Right Angles
You will learn about four different types of
angles. The first is a right angle. Right angles
measure exactly 90°.
The angles at the corners of this rectangle are
right angles.
Acute Angles
Angles that have a measure between 0° and
90° are called acute angles.
The angles at the corners of a yield sign are
acute angles. They are smaller than right
angles.
Obtuse Angles
Obtuse angles are big. They measure between
90° and 180°
The angles formed on the corners of a stop
sign are all obtuse angles.
Straight Angles
Straight angles have a measurement of exactly
180°.
A straight angle looks like this:
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