Similar Triangles സദൃശത്രികോണങ്ങൾ
An interactive, animated self-study guide. Everything you need is here: the basics from earlier classes, every idea in the chapter with real-life examples, animated solutions to every textbook question, a revision sheet, and a model test with a fully solved paper.
How to use this guide
🎬 Watch the animations
Every idea has a step-by-step animation. Press Next ▶ to move one step at a time, or ▶▶ Auto play to watch it like a video. You can go back any time.
🖐️ Play with the figures
Orange dots can be dragged. Sliders change the scale factor. Watching the numbers change is the fastest way to feel why the theorems are true.
✍️ Try before you see
Questions come with a Show answer button. Always attempt the question in your notebook first, then check. The quizzes give instant feedback.
📖 Textbook links
Purple മലയാളം words are the exact terms used in your textbook, so you can match every page here with the book (pages 99–118).
Learning path
Follow the pages in order. If you are confident about triangles from Class 8, you may skim pages 1–4, but do try their quizzes.
The chapter in one picture
Two triangles are similar (സദൃശം) when one is an enlargement or reduction of the other: the angles stay the same and every side is multiplied by the same number (the scale factor). This chapter proves exactly when that happens and how to use it.
Quick glossary (Malayalam ↔ English)
| Textbook term | English | Meaning |
|---|---|---|
| സദൃശത്രികോണങ്ങൾ | Similar triangles | Same angles; sides in the same ratio |
| തുല്യത്രികോണങ്ങൾ | Congruent (equal) triangles | Same angles and same side lengths |
| തോത് / scale factor | Scale factor | The number every side is multiplied by |
| അംശബന്ധം | Ratio | Comparison of two lengths, e.g. 3 : 4 or ¾ |
| സമാന്തരവരകൾ | Parallel lines | Lines that never meet; same slope |
| ലംബം | Perpendicular | At 90° |
| കർണ്ണം | Hypotenuse | Longest side of a right triangle |
| പരപ്പളവ് | Area | Space inside the shape |
| പരിവൃത്തം | Circumcircle | Circle through all three vertices |
| സമഭാജി | Bisector | Line that cuts an angle into two equal halves |
Made for self-learning. Works offline – every page is a single file. Author of the study material: Claude, prepared for Madhu's family study folder, September 2026.