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CBSE Class 11 » CBSE Class 11 Study Materials » Mathematics » Acute Angle
CBSE

Acute Angle

In this article, we will discuss the acute angle and its properties.

Table of Content
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The word ‘Angle’ is derived from the Latin word “angulus”, which means “corner”. An angle is a figure created by two rays, called the sides of the angle, that share a common endpoint, called the vertex of the angle, in Euclidean geometry. The angles that are generated by two rays lie in the plane in which the rays are present. Dihedral angles are what they’re called. Two intersecting curves can also define an angle, which is the angle formed by rays lying tangent to the curves at their junction.

A plane angle is defined by Euclid as the inclination in a plane of two lines that intersect and do not lay straight with regard to each other.

The arms and the vertex are the two main components of an angle.

The arms of the angle are the two rays that meet at the same point to produce the angle. The two rays have a common terminal called the vertex.

Identifying a angle:-

Angles can also be distinguished in geometric shapes by the labels linked to the three points that define them. The angle enclosed by the rays AB and AC (i.e. the lines from point A to point B and point A to point C) at vertex A, for example, is abbreviated <BAC.

Types of angle:-

There are various types of angles based upon the measurement of their angular value –

  • A zero angle is a non-turned angle that is equal to 0°.
  • An acute angle is one that is less than a right angle (less than 90°). (“acute” meaning “sharp”).
  • A right angle is defined as a 90° or
    • π /2-radian angle. Normal, orthogonal, and perpendicular are terms used to describe two lines that make a right angle.
  • An obtuse angle is one that is greater than a right angle but smaller than a straight angle (between 90° and 180°). (“obtuse” meaning “blunt”).
  • A straight angle is defined as one-half of a turn (180° or radians).
  • A reflex angle is an angle that is larger than a straight angle but less than one turn (between 180° and 360°).
  • A full angle, complete angle, round angle, or perigon is an angle equal to one turn (360° or 2 radians).
  • An oblique angle is an angle that is not a multiple of a right angle.

ACUTE ANGLE: –

Acute angles are those that are smaller than 90 degrees. When the time is 11 o’clock, for example, the angle produced between the hour hand and the minute hand is acute. In other words, acute angles are 30°, 40°, 57°, and so on. When two rays meet at a vertex, they make an angle. An acute angle is defined as one that is less than 90 degrees. An acute angle is one that is less than 90 degrees, i.e. one that is between 0 and 90 degrees. 60 degrees, 30 degrees, 45 degrees, and so on are some examples.

 An acute triangle is one in which all of the inner angles are smaller than 90 degrees. Because the interior angles measure 60 degrees, an equilateral triangle is an acute triangle. An acute angle is defined as one that is less than 90 degrees, or less than a straight angle, as stated in the preceding section. Acute angle degrees include 63°, 31°, 44°, 68°, 83°, and 85°. As a result, the acute angle degree spans from 0 to less than 90 degrees. 

An acute angle is defined as one that is less than 90 degrees, or less than a straight angle, as stated in the preceding section. Acute angle degrees include 63°, 31°, 44°, 68°, 83°, and 85°. As a result, the acute angle degree spans from 0 to less than 90 degrees.

Real-life examples of acute angle: –

In geometry, acute angles are defined as those that are larger than 0° but less than 90°. As a result, acute angles include 45°, 5°, 28°, 49°, and 89°.

Here are some examples of sharp angles in real life.

  • A watermelon slice, chopped into small pieces.
  • Some examples of the angles made between the hour and minute hands of a clock.
  • When a bird’s beak is fully open.
  • When a crocodile’s mouth is open, an angle is generated.
  • The pairs of an open scissors look like an acute angle
  • When a pizza is split into 5 or more pieces, each slice forms an acute angle. Each pizza slice creates an acute angle.

CONCLUSION: –

Two rays or line segments make up an acute angle. At one endpoint of an acute angle, the two line segments meet. The angle’s base is formed by one line segment, while the angle’s arm is formed by the other line segment. The angle measures on the protractor can be read anti-clockwise to determine an acute angle. With the aid of a protractor, the acute angle can be built and measured. Sharp angles are referred to as acute angles.

faq

Frequently asked questions

Get answers to the most common queries related to the CBSE 11th Examination Preparation.

What is an acute angle?

Ans:- Acute angles can be defined as those that are smaller than 90 degrees.

What are the properties of acute angle?

Ans:- The essential feature of an acute angle is that its measurement ranges from 0 to 90 degrees. In the instance o...Read full

How many acute angles does a right triangle have at the most?

Ans:- At least two acute angles must be present in a right triangle. One angle should be 90 degrees, while the other...Read full

Can we consider 0 degrees angle as an acute angle?

Ans:- Yes, a 0-degree angle is an acute angle. The range of acute angles starts at 0 and ends with values less than ...Read full

45° is an acute angle or not? Justify your Answer.

Ans: Yes, 45° is an acute angle, we know that acute angle is angle between 0 to 90 degree so 45° is an acute angle...Read full

Ans:- Acute angles can be defined as those that are smaller than 90 degrees.

Ans:- The essential feature of an acute angle is that its measurement ranges from 0 to 90 degrees. In the instance of the acute angle triangle, the measures of all three interior angles range from 0 to 90 degrees, but the sum of all interior angles is always 180 degrees.

Ans:- At least two acute angles must be present in a right triangle. One angle should be 90 degrees, while the other two should always be between 0 and 90 degrees.

Ans:- Yes, a 0-degree angle is an acute angle. The range of acute angles starts at 0 and ends with values less than 90.

Ans: Yes, 45° is an acute angle, we know that acute angle is angle between 0 to 90 degree so 45° is an acute angle.

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