Triangles

Triangles explained with definitions, properties, congruence rules, similarity concepts, and examples for strong geometric understanding.

1.What is a Triangle?
Understand what a triangle is in geometry with a clear definition, simple diagrams and real-life examples.
2.Parts of a Triangle (Vertices, Sides, Angles, Interior and Exterior)
Learn the basic parts of a triangle—vertices, sides, angles, interior and exterior regions—explained in a simple student-friendly way with clear diagrams and examples.
3.Naming and Notation of Triangles
Learn how triangles are named and notated in geometry, including vertices, sides, and angle naming conventions explained in clear student-friendly notes with diagrams.
4.Scalene Triangle
Understand the scalene triangle, its definition, properties, and visual meaning with simple diagrams and real-life examples explained in student-friendly notes.
5.Isosceles Triangle
Learn what an isosceles triangle is with simple definitions, clear geometric properties, diagrams, and real-life examples explained in student-friendly notes.
6.Equilateral Triangle
Learn the definition and properties of an equilateral triangle with simple explanations, diagrams, and examples in an easy-to-understand format.
7.Acute-Angled Triangle
Learn what an acute-angled triangle is with clear definitions, diagrams, key properties and real-life examples explained in simple student-friendly notes.
8.Right-Angled Triangle
Learn what a right-angled triangle is with clear definitions, diagrams, key properties, and real-life examples explained in simple student-friendly notes.
9.Obtuse-Angled Triangle
Learn what an obtuse-angled triangle is, with clear definitions, diagrams, key properties, and real-life examples explained in simple, student-friendly notes.
10.Angle Sum Property of a Triangle
Understand the angle sum property of a triangle with simple explanations, formulas, diagrams, and clear reasoning written in student-friendly notes.
11.Exterior Angle Property of a Triangle
Learn the exterior angle property of a triangle with clear definitions, diagrams, and simple explanations.
12.Triangle Inequality and Side Relations
Learn the triangle inequality theorem and important side–angle relationships with clear explanations, diagrams, and formulas .
13.Altitude of a Triangle
Learn what an altitude of a triangle is, how it is constructed, its properties, and where the altitudes meet, explained with simple diagrams and student-friendly notes.
14.Median of a Triangle
Learn about the median of a triangle: its definition, how to construct it, its properties, and the centroid in clear student-friendly notes with diagrams.
15.Perpendicular Bisector of a Triangle
Learn what a perpendicular bisector is in a triangle, how it is constructed, its properties, and where perpendicular bisectors meet, explained in simple student-friendly notes.
16.Angle Bisector of a Triangle
Learn what an angle bisector in a triangle is, how it is constructed, its properties, and the incentre explained using simple diagrams and student-friendly notes.
17.Centroid of a Triangle
Learn what the centroid of a triangle is, how to construct it, and its important properties explained with simple diagrams and student-friendly notes.
18.Incentre of a Triangle
Learn what the incentre of a triangle is, how angle bisectors form it, and its properties including the incircle, explained with simple diagrams and student-friendly notes.
19.Circumcentre of a Triangle
Learn what the circumcentre of a triangle is, how perpendicular bisectors form it, and its properties including the circumcircle, explained with clear diagrams and student-friendly notes.
20.Orthocentre of a Triangle
Learn what the orthocentre of a triangle is, how altitudes form it, and how its position changes with different triangle types, explained with simple diagrams and student-friendly notes.
21.What is Congruence of Triangles?
Understand the meaning of congruent triangles with clear definitions, visual explanations, properties, and simple student-friendly notes.
22.SSS Congruence Rule
Learn the SSS (Side-Side-Side) congruence rule for triangles with clear definitions, diagrams, and simple student-friendly explanations.
23.SAS Congruence Rule
Learn the SAS (Side-Angle-Side) congruence rule for triangles with clear definitions, diagrams, and simple student-friendly explanations.
24.ASA Congruence Rule
Learn the ASA (Angle-Side-Angle) congruence rule for triangles with clear definitions, diagrams, and student-friendly explanations.
25.AAS Congruence Rule
Learn the AAS (Angle-Angle-Side) congruence rule for triangles with clear definitions, diagrams, and student-friendly explanations.
26.RHS Congruence Rule
Learn the RHS (Right angle–Hypotenuse–Side) congruence rule for right triangles with clear definitions, diagrams, and simple student-friendly explanations.
27.What is Similarity of Triangles?
Understand the meaning of similarity in triangles with clear definitions, diagrams, and simple student-friendly notes.
28.AAA Similarity Rule
Learn the AAA (Angle-Angle-Angle) similarity rule for triangles with simple definitions, diagrams, and student-friendly explanations.
29.SAS Similarity Rule
Learn the SAS (Side-Angle-Side) similarity rule for triangles with clear definitions, diagrams, and simple student-friendly explanations.
30.SSS Similarity Rule
Learn the SSS (Side-Side-Side) similarity rule for triangles with clear definitions, diagrams, and simple student-friendly notes.
31.Properties of Similar Triangles
Learn all key properties of similar triangles, including angle equality, side ratios, area relationships, and practical implications, explained with simple student-friendly notes.
32.Pythagoras Theorem
Learn the Pythagoras Theorem with simple definitions, diagrams, formula, and student-friendly explanations for right-angled triangles.
33.Converse of Pythagoras Theorem
Learn the converse of the Pythagoras Theorem with clear definitions, diagrams, and simple student-friendly explanations.
34.Area of a Triangle
Learn all the different formulas to find the area of a triangle, including base-height formula, Heron’s formula, coordinate geometry formula, and simple student-friendly explanations.
35.Heron's Formula
Learn Heron's Formula to find the area of a triangle using only its side lengths, with clear steps and student-friendly explanations.
36.Special Right Triangles (30-60-90 and 45-45-90)
Learn the properties and side ratios of 30-60-90 and 45-45-90 special right triangles with simple diagrams and student-friendly explanations.