An angle that is formed inside a triangle by the intersection of its sides, is called an interior angle of a triangle.
A triangle is formed by connecting the endpoints of three line segments as a closed geometric shape. The intersection of every two sides of a triangle forms an angle internally. Hence, the angle is called an interior angle of triangle. It is also called as an internal angle of a triangle.
In a triangle, the three line segments are intersected at three locations on a plane. Hence, three interior or internal angles are formed inside a triangle.
For understanding the concept of internal angles of a triangle, let’s construct a triangle geometrically.
Thus, a triangle, denoted by $\Delta MLN$ is formed geometrically.
In this triangle, $\angle LMN$, $\angle MLN$ and $LNM$ are called interior or internal angles of the triangle.
In this example, the internal angles $\angle LMN$, $\angle MLN$ and $LNM$ are unknown but they can be measured by a protractor.
The interior angles in $\Delta MLN$ are measured that
$(1).\,\,\,$ $LMN \,=\, 42^°$
$(2).\,\,\,$ $MLN \,=\, 56^°$
$(3).\,\,\,$ $LNM \,=\, 82^°$
Geometrically, the sum of interior angles in a triangle is equal to $180^°$.
A best free mathematics education website for students, teachers and researchers.
Learn each topic of the mathematics easily with understandable proofs and visual animation graphics.
Learn how to solve the maths problems in different methods with understandable steps.
Copyright © 2012 - 2022 Math Doubts, All Rights Reserved