Skip to main content
Chapter 4 of 8
Flashcards

Geometry

Tamil Nadu Board · Class 10 · Mathematics

Flashcards for Geometry — Tamil Nadu Board Class 10 Mathematics. Quick Q&A cards covering key concepts, definitions, and formulas.

44 questions26 flashcards5 concepts

Interactive on Super Tutor

Studying Geometry? Get the full interactive chapter.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for flashcards and more.

1,000+ Class 10 students started this chapter today

A diagram illustrating the steps for the proof of the Basic Proportionality Theorem, involving construction of perpendiculars and joining vertices to form triangles with equal areas.
Super Tutor

Super Tutor has 5+ illustrations like this for Geometry alone — flashcards, concept maps, and step-by-step visuals.

See them all
26 Flashcards
Card 1Basic Proportionality Theorem

In triangle ABC, DE is parallel to BC. If AD = 4 cm, DB = 6 cm, and AE = 5 cm, find EC using the Basic Proportionality Theorem.

Answer

By Basic Proportionality Theorem (Thales Theorem): AD/DB = AE/EC Step 1: Write the proportion → 4/6 = 5/EC Step 2: Cross multiply → 4 × EC = 6 × 5 Step 3: 4 × EC = 30 Step 4: EC = 30/4 = 7.5 cm Verifi

Card 2Similar Triangles - SSS Criterion

Determine if triangles ABC and PQR are similar given: AB = 6 cm, BC = 8 cm, AC = 10 cm and PQ = 9 cm, QR = 12 cm, PR = 15 cm. State the criterion used.

Answer

Check if corresponding sides are proportional using SSS similarity criterion. Step 1: Find ratios of corresponding sides → AB/PQ = 6/9 = 2/3 → BC/QR = 8/12 = 2/3 → AC/PR = 10/15 = 2/3 Step 2: Check if

Card 3Application of Similar Triangles

A boy 1.2 m tall stands 8 m away from a lamp post 7.2 m high. Find the length of his shadow using similar triangles.

Answer

Use similar triangles: △ABE ~ △CDE where E is the tip of shadow. Let shadow length = x Step 1: Set up proportion from similar triangles → Height of lamp/Shadow from lamp = Height of boy/Shadow of boy

Card 4Similarity Criteria - AA Criterion

When do you use the AA (Angle-Angle) similarity criterion? Provide an example where two triangles satisfy this criterion.

Answer

Use AA similarity when: - You know two pairs of corresponding angles are equal - The third angle will automatically be equal (since angle sum = 180°) - You cannot or don't need to know side lengths E

Card 5Converse of Basic Proportionality Theorem

Apply the converse of the Basic Proportionality Theorem: In triangle ABC, D is on AB and E is on AC such that AD/DB = 3/4 and AE/EC = 3/4. Prove DE is parallel to BC.

Answer

Given: AD/DB = 3/4 and AE/EC = 3/4 Step 1: Identify what you're given → AD/DB = AE/EC (both equal 3/4) Step 2: Apply Converse of BPT → If a line divides two sides of a triangle in the same ratio, th

Card 6Angle Bisector Theorem

In triangle ABC, AD is the angle bisector of angle A. If AB = 8 cm, AC = 12 cm, and BC = 10 cm, find BD and DC.

Answer

Use Angle Bisector Theorem: AB/AC = BD/DC Given: AB = 8 cm, AC = 12 cm, BC = 10 cm Let BD = x, then DC = 10 - x Step 1: Apply Angle Bisector Theorem → 8/12 = x/(10-x) Step 2: Simplify the left side

Card 7Pythagoras Theorem

Solve: A right triangle has a hypotenuse of 13 cm and one leg of 5 cm. Find the length of the other leg using Pythagoras Theorem.

Answer

Use Pythagoras Theorem: a² + b² = c² where c is hypotenuse Given: Hypotenuse c = 13 cm, One leg a = 5 cm, Find b = ? Step 1: Write Pythagoras formula → a² + b² = c² Step 2: Substitute known values

Card 8Pythagoras Theorem - Real World Application

A ladder 5 m long is placed against a wall with its base 3 m away from the wall. How high does the ladder reach on the wall?

Answer

Use Pythagoras Theorem: a² + b² = c² Given: Ladder length (hypotenuse) c = 5 m, Distance from wall a = 3 m, Height b = ? Step 1: Identify the right triangle → Ladder is hypotenuse → Distance from wa

+18 more flashcards available

Practice All

Frequently Asked Questions

What are the important topics in Geometry for Tamil Nadu Board Class 10 Mathematics?
Key topics in Geometry include Chapter 4 Geometry — Complete Topic Overview, Geometry Chapter - Concept Hierarchy, Geometry Chapter Overview. These are the concepts Tamil Nadu Board Class 10 examiners draw on most — study them first, then practise related questions.
How to score full marks in Geometry — Tamil Nadu Board Class 10 Mathematics?
Understand the core concepts first, then work through the 44 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.
How many flashcards are available for Geometry?
There are 26 flashcards for Geometry covering key definitions, formulas, and concepts. Use them daily for 10–15 minutes for best results.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

For serious students

Get the full Geometry chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for Tamil Nadu Board Class 10 Mathematics.