A carpenter design a triangular table that had actually one leg. He provided a special allude of the table which to be the center of gravity, due to which the table was balanced and also stable.

You are watching: Point of concurrency of the angle bisectors of a triangle

Do you recognize what this special point is known as and how do you uncover it?

This special allude is the suggest of concurrency the medians.

In this page, friend will discover all about the allude of concurrency.This mini-lesson will likewise cover the allude of concurrency that perpendicular bisectors, the point of concurrency the the edge bisectors of a triangle, and interesting exercise questions.Let’s begin!

Lesson Plan

1.What Is the allude of Concurrency?
2.Important note on the allude of Concurrency
3.Solved examples on the point of Concurrency
4.Challenging questions on the allude of Concurrency
5. Interactive inquiries on the allude of Concurrency

What Is the suggest of Concurrency?

The allude of concurrency is apoint where three or an ext linesor raysintersect with each other.

For example, referring to the image shown below, allude A is the allude of concurrency, and also all the three rays l, m, n space concurrent rays.

Triangle Concurrency Points

Four different types of line segments can be attracted for atriangle.

Please refer to the following table because that the above statement:

Name the the heat segmentDescriptionExample
Perpendicular BisectorThese space the perpendicular lines drawn to the political parties of the triangle.


Angle BisectorThese lines bisect the angle of the triangle.


MedianThese heat segments connect any type of vertex of the triangle come the mid-point of the opposite side.


AltitudeThese room the perpendicular lines drawn to the opposite next from the vertices of the triangle.


As four different types of heat segments can be attracted to a triangle, similarly we have actually four various points the concurrency in a triangle.

These concurrent clues are described as different centers according to the lines meeting at the point.

The different points of concurrency in the triangle are:


1. Circumcenter

The circumcenter is the point of concurrency that theperpendicular bisectors of every the political parties of a triangle.


For an obtuse-angled triangle, the circumcenter lies external the triangle.

For a right-angled triangle, the circumcenter lies in ~ the hypotenuse.

If we attract a circle taking a circumcenter together thecenter and touching the vertices of the triangle, we gain a circle known as a circumcircle.


2. Incenter

The incenter is the point of concurrency that theangle bisectors of all the internal anglesof thetriangle.

In other words, the suggest where 3 angle bisectorsof the angle of the triangle accomplish areknown as the incenter.

The incenter always lies within the triangle.


The circle the is drawn taking the incenter together the center, is recognized as the incircle.


3. Centroid

The point where three mediansof the triangle meet isknown as the centroid.


In Physics, we use the term"center that mass" and also itlies in ~ the centroid the the triangle.

Centroid always lies in ~ the triangle.

It always divides each median right into segments in the ratio of 2:1.

4. Orthocenter

The suggest where three altitudesof the triangle satisfy isknown together the orthocenter.

For an obtuse-angled triangle, the orthocenter lies exterior the triangle.


Observe the different congruency clues of a triangle v the adhering to simulation:


Example 1

Ruth demands to determine the figure which accurately represents the formation of an orthocenter. Can you aid her figure out this?



The allude where the 3 altitudes that a triangle satisfy are recognized as the orthocenter.

Therefore, the orthocenter is a concurrent suggest of altitudes.


\(\therefore\)Figure C to represent an orthocenter.
Example 2

Shemron hasa cake that is shaped choose an it is provided triangle of sides \(\sqrt3 \text in\) each. He desires to find out the radiusofthe circular basic of the cylindricalbox which will certainly contain this cake.



Since it i am one equilateral triangle, \( \text AD\) (perpendicular bisector)will go with the circumcenter \(\text O \).

The circumcenter will certainly divide the equilateral triangle into three equal triangles if joined through the vertices.


\<\beginalign* \text area \triangle AOC &= \text area \triangle AOB = \text area \triangle BOC \endalign*\>


\<\beginalign* \text area of \triangle ABC&= 3 \times \text area of \triangle BOC \endalign* \>

Using the formula because that the area the an it is provided triangle\<\beginalign* &= \dfrac\sqrt34 \times a^2 \hspace3cm ...1 \endalign* \>

Also, area that triangle \<\beginalign* &= \dfrac12 \times \text base \times \text height \hspace1cm ...2 \endalign* \>

By using equation 1 and 2 because that \(\triangle \textBOC\) we get,

\<\beginalign* \dfrac\sqrt34 \times a^2 &= 3\times \dfrac12 \times a\times OD\\OD &= \dfrac12\sqrt3 \times a\hspace2cm ...3\endalign*\>

Now, by applying equation 1 and also 2 because that \(\triangle \textABC\) we get,

\(\textArea the the \triangle\text ABC \) \<= \dfrac12 \times \text base \times \text elevation =\dfrac\sqrt34\times a^2 ...4\>

Using equation 3 and also 4, we get

\<\beginalign*\dfrac 12\times a\times (R+OD) &= \dfrac \sqrt 34\times a^2 \\\dfrac12 a\times \left( R+\dfrac a2\sqrt3\right) &= \dfrac\sqrt34\times a^2\\R &= \dfrac a\sqrt3 \endalign*\>


\< \beginalign*a & = \sqrt3\endalign*\>

\(\therefore\) \(\text R = 1 \textin\)

Example 3

A teacher drew 3 medians of a triangle and also asked his students to name the concurrent allude of these three lines. Have the right to you name it?


The allude where three mediansof the triangle fulfill areknown as the centroid.

The concurrent suggest drawn through the teacher is-

Example 4

For an equilateral \(\triangle \textABC\), if p is the orthocenter, discover the value of \( \angle BAP\).


For an it is provided triangle, all the 4 points (circumcenter, incenter, orthocenter, and centroid) coincide.

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Therefore, allude P is additionally an incenter of this triangle.

Since this is an equilateral triangle in which all the angles are equal, the value of \( \angle BAC = 60^\circ\)