1.
Types of
Angles
Vaishika G

2.
Introduction
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• In geometry, there are various types of angles, based on
measurement.
• The names of basic angles are Acute angle, Obtuse
angle, Right angle, Straight angle, reflex angle and full
rotation.
• An angle is geometrical shape formed by joining two rays
at their end-points. An angle is usually measured in
degrees.
• There are various types of angles in geometry. Angles
form the core part of the geometry in mathematics. They
are the fundamentals that eventually lead to the
formation of the more complex geometrical figures and
shapes.

3.
Acute Angle

4.
Acute angle (contd..)
An acute angle is defined as an angle that measures
less than 90 degrees i.e. measure between 0° to 90°. Some
of the examples are 60°, 30°, 45°, etc. A triangle formed by
all the interior angles measuring less than 90° is called
an acute triangle. For example, an equilateral triangle is an
acute triangle since the interior angles measure 60°.
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5.
Obtuse
Angle
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6.
Obtuse angle (contd..)
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In geometry, an obtuse angle is defined as an angle that is
greater than 90° and less than 180°. Often during a day in a 24
hours duration, we can see a clock framing many obtuse angle
degrees between a minute hand and an hour hand.

7.
Right Angle
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8.
Right angle (contd..)
A right angle is an angle that measures 90 degrees. It
is the most commonly seen angle in our day-to-day life. It
can be seen in the corners of a room, the edges of boxes,
the screen of a mobile phone, and so on. The sides of a
square and a rectangle always form a right angle with each
other. In radians, it is represented as π/2.
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9.
Reflex Angle
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10.
Reflex angle (contd..)
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A reflex angle is an angle that lies between 180° and 360°.
A reflex angle and the corresponding angle that lies on the other
side of it together form a complete angle of 360°. It should be
noted that a reflex angle always has an acute angle, an obtuse
angle, or a right angle on the other side of it.

11.
Straight
Angle
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12.
Straight angle (contd..)
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A straight angle measures 180° and looks like a straight
line, therefore, it is a mathematical way of expressing a straight
line. It is an angle whose arms lie in opposite directions from the
vertex and they join together to form 180°. Whenever two rays
join together they form an angle and the angle subtended by two
rays in opposite directions is called a straight angle.

13.
Complete
Angle
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14.
Complete angle (contd..)
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If after one whole rotation, the final ray coincides with the
incident or initial ray, then the angle so formed is known as the
complete angle. The other names are a full angle and a round
angle. The angle is equal to 2π radians = 360 degrees
corresponding to the central angle of an entire circle. Four right
angles or two straight angles make a complete angle. The angle
is similar to a zero angle but the difference is the amount of
rotation.

15.
Thank you
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Vaishika G