In Maths, a straight angle is an angle same to 180 degrees. It is called straight due to the fact that it shows up as a right line. Basically, as per angles meaning in maths, once two rays room joined end to end, they kind an angle. Hence, the 2 rays of the 180-degree angle are subtended towards the the contrary direction, wherein the rays are joined come each other at endpoints.

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In radians, the 180-degree edge is measure up in pi (π). To allude the opposite way, the directly angle alters the direction. A 180 degree is additionally considered together supplementary. Apart from this angle, over there are 5 different types of angle in geometry i m sorry you have the right to learn here.

Facts:A directly angle constantly forms a directly line.The worth of the directly angle is 180°.The arms of the directly angle lied opposite to each various other from the crest point.The right angle measured anticlockwise is the confident straight angle i.e.180°.The right angle measure up clockwise is a an adverse straight edge i.e.-180°.

Straight edge Definition

In geometry, a straight edge is an angle, whose vertex suggest has a value of 180 degrees. Basically, it forms a straight line, whose political parties lie in opposite directions from the vertex. That is also termed as “flat angles”


A horizontal line and also a vertical heat are constantly straight lines and also therefore castle are instances of straight angles.


In degrees, the straight angle is represented as 180° and also in radians, it is denoted with pi (π).

Straight edge Examples

Some of the straight edge examples in our day-to-day life are:

A level surface has actually an angle of 180 degreesA directly stick has an angle which is directly or 180 degreeA plane inclined staircase to represent a straight angleAngle created in a see-saw

A straight angle is different from the straight line, together it measures 180 degrees and a right line is a connector of 2 points.


Straight angle theorem states that every the directly angles space 180 degrees. If the legs of angle, space pointing exactly in opposing directions, then it forms a directly angle. A straight angle is represented as 180° (in degrees) or π (in radians).

One great example is the heat segment in geometry, the endpoints of i m sorry extends in the direction of the opposite direction. 

Properties of directly Angles

Some vital properties of directly angles are as follows:

A right angle steps exactly fifty percent of a revolutionA straight angle is created by revolving one ray by 180° with respect to an additional rayIn a right angle, the arms expand in the contrary directionsA right angle modifies the direction of a pointA straight angle can additionally be developed by joining two best angles

Six varieties of Angles

An edge is developed when two line segments room joined at a single endpoint or when two heat segments are linked at a single endpoint. The point where the 2 lines satisfy is dubbed the peak of the angle. There are basically 6 different species of angle whose peak values are different, respectively, and also they are;

Acute edge (less than 90°)Obtuse edge (more than 90°)Right edge (equal come 90°)Straight Angle 
(exact 180°)Reflex angle (greater 보다 180°) and Full edge (Exact 360°)

An angle with 0° is referred to as a zero angle, method it doesn’t type an angle. These space the general group of angles.

In geometry, we compare 2 angles based upon your conditions. Part angles are defined in regards to their similarity, called as a congruent angle, which has actually the same angle. Then, us have adjacent angles, which are surrounding to each other. Safety angles, whose amount is equal to 90°.

Can we take into consideration a Triangle made from a straight Angle?

A right angle has actually a measure of 180°and the sum of internal angles of a triangle is additionally 180°. Yet we cannot think about straight angle as a straight angle triangle because, for a triangle, the figure should form an fastened structure.

Triangle is a closeup of the door three-sided figure, which has three distinct points which space not collinear with each other. But, in the situation of the straight line, the points space collinear and hence castle cannot type a close up door structure. Therefore, there is no triangle formed.

How to build a straight Angle?

The procedures to construct a right Angle, room as follows:

Draw a straight-line OB making use of a ruler, with an arrowhead in ~ BNow location the protractor on this heat such that the baseline that the protractor is adjusted over OB. The allude B have to be encountering towards the 0°of the protractor.Now mark the point, starting from 0° and also moving towards 180 degrees. On reaching 180°, note a suggest A on the paper.Now, join the vertex of the line OB through the significant point A. The 2nd ray OA should have actually arrowhead in ~ A.

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A directly angle is one angle equal to 180 degrees. That looks choose a straight line. In radian, the is measured as π angle.