Triangles
ICSE · Class 9 · Mathematics
Summary of Triangles for ICSE Class 9 Mathematics. Key concepts, important points, and chapter overview.
Interactive on Super Tutor
Studying Triangles? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for chapter summary and more.
1,000+ Class 9 students started this chapter today
Learn better with visuals Super Tutor has hundreds of illustrations like this across every chapter — all free to try.
Get startedOverview
A triangle is a plane figure bounded by three straight line segments. It has three sides and three vertices. The chapter builds understanding of how sides and angles are related, how medians and altitudes meet at special points, how angle properties work, and how triangle congruence is proved using
Key Concepts
A triangle is a plane figure
A triangle is a plane figure bounded by three straight line segments. It has three vertices and three sides. Triangle ABC is the standard example, wit
The greater side has the greater
The greater side has the greater angle opposite to it. If all angles are different, then the sides are also different, and the greater angle has the g
The median of a triangle corresponding
The median of a triangle corresponding to any side is the line joining the mid-point of that side with the opposite vertex. A triangle has three media
The centroid is the point where
The centroid is the point where the three medians meet. It divides each median in the ratio 2:1. For triangle ABC with centroid G and mid-points D, E,
An altitude of a triangle corresponding
An altitude of a triangle corresponding to any side is the length of the perpendicular drawn from the opposite vertex to that side. A triangle has thr
Learning Objectives
- Identify a triangle, its sides, and its vertices
- Understand the relation between unequal sides and unequal angles
- Use the properties of isosceles and equilateral triangles
- Define and use median, centroid, altitude, and orthocentre
- Apply the angle sum property of a triangle
Frequently Asked Questions
What are the important topics in Triangles for ICSE Class 9 Mathematics?
How to score full marks in Triangles — ICSE Class 9 Mathematics?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Triangles
Practice Quiz
Test yourself with a quick quiz
Important Questions
Practice with board exam-style questions
Revision Notes
Key points for last-minute revision
Formula Sheet
All formulas in one place
Concept Maps
See how topics connect visually
Study Plan
Step-by-step plan to ace this chapter
Flashcards
Quick-fire cards for active recall
Syllabus
What topics to cover
NCERT Solutions
Every textbook question solved step by step
For serious students
Get the full Triangles chapter — for free.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for ICSE Class 9 Mathematics.