Skip to main content
Chapter 11 of 14
Flashcards

Triangles

Karnataka Board · Class 10 · Mathematics

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

45 questions20 flashcards5 concepts
20 Flashcards
Card 1Basic Proportionality Theorem

In triangle ABC, DE is parallel to BC. If AD = 3 cm, DB = 6 cm, and AE = 4 cm, find EC.

Answer

Step 1: Apply Basic Proportionality Theorem - When DE || BC, then AD/DB = AE/EC Step 2: Substitute values → 3/6 = 4/EC Step 3: Cross multiply → 3 × EC = 6 × 4 = 24 Step 4: Solve for EC → EC = 24/3 = 8

Card 2Similar Figures

Prove that all circles are similar. Explain why with an example.

Answer

Step 1: Definition of similarity - Two figures are similar if they have same shape but not necessarily same size Step 2: All circles have the same shape (perfectly round) regardless of their radius St

Card 3Basic Proportionality Theorem

In triangle PQR, ST is drawn parallel to QR. If PS/SQ = 2/3 and PT/TR = 2/3, verify that ST || QR using the converse of Basic Proportionality Theorem.

Answer

Step 1: Given PS/SQ = 2/3 and PT/TR = 2/3 Step 2: Check if the ratios are equal → PS/SQ = PT/TR = 2/3 ✓ Step 3: Apply Converse of Basic Proportionality Theorem: If a line divides two sides of a triang

Card 4AA Similarity Criterion

When do you use the AA similarity criterion? Solve: Triangle ABC has angles 60° and 80°. Triangle DEF has angles 60° and 40°. Are they similar?

Answer

Use AA criterion when: Two angles of one triangle equal two angles of another triangle Step 1: Find third angle of ABC → 180° - 60° - 80° = 40° Step 2: Angles of ABC: 60°, 80°, 40° Step 3: Angles of D

Card 5SSS Similarity Criterion

Apply SSS similarity criterion: Triangle ABC has sides 6 cm, 8 cm, 10 cm. Triangle PQR has sides 9 cm, 12 cm, 15 cm. Are they similar?

Answer

Step 1: Check if corresponding sides are proportional Step 2: Arrange sides in order: ABC (6, 8, 10) and PQR (9, 12, 15) Step 3: Calculate ratios: AB/PQ = 6/9 = 2/3 BC/QR = 8/12 = 2/3 CA/RP = 10/15 =

Card 6Applications of Similar Triangles

A 1.5 m tall person casts a 2 m shadow. At the same time, a building casts a 40 m shadow. Find the height of the building using similar triangles.

Answer

Step 1: Set up similar triangles - person and shadow form one triangle, building and shadow form another Step 2: Both triangles are similar (same sun angle) Step 3: Write proportion: Height of person/

Card 7SAS Similarity Criterion

Use SAS similarity criterion: Triangle ABC has AB = 4 cm, AC = 6 cm, ∠A = 70°. Triangle DEF has DE = 6 cm, DF = 9 cm, ∠D = 70°. Prove similarity.

Answer

Step 1: Check if one angle is equal and including sides are proportional Step 2: Given angles: ∠A = ∠D = 70° ✓ Step 3: Check including sides ratio: AB/DE = 4/6 = 2/3 AC/DF = 6/9 = 2/3 Step 4: Includin

Card 8Applications of Similar Triangles

In trapezium ABCD with AB || CD, diagonals intersect at O. If AO = 6 cm, OC = 9 cm, find BO/OD ratio.

Answer

Step 1: In trapezium with parallel sides, diagonals create similar triangles Step 2: Triangles AOB and COD are similar (AB || CD creates equal corresponding angles) Step 3: For similar triangles: AO/O

+12 more flashcards available

Practice All

Get detailed flashcards for Triangles

Super Tutor gives you interactive content for every chapter of Karnataka Board Class 10 Mathematics — summaries, quizzes, flashcards, and more.

Try Super Tutor — It's Free

Frequently Asked Questions

What are the important topics in Triangles for Karnataka Board Class 10 Mathematics?

Triangles covers several key topics that are frequently asked in Karnataka Board Class 10 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.

Start by understanding all key concepts. Practise previous year questions from this chapter. Revise formulas and definitions regularly. Use flashcards for quick revision before the exam.

There are 20 flashcards for Triangles 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.