4 min read
Number
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
Choose Your Level
Number
What is it?
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
In simple words
- R=13, r=5: half-chord 12, chord 24.
- Pythagoras again
- same centre
- outer chord tangent to inner
Important terms
Number: R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
What you should learn
- Define and explain number.
- Apply number to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Examples
- Pythagoras again
- same centre
- outer chord tangent to inner
CORE UNDERSTANDING
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Recommended for Class 10
Full school-level explanation
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
Learn the idea, then use it:
WHAT — NUMBER
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
HOW — Use the idea
Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check the result.
CORE UNDERSTANDING
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
Remember
- Pythagoras again
- same centre
- outer chord tangent to inner
Examples
- Pythagoras again
- same centre
- outer chord tangent to inner
- NUMBER: R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
EXAM APPLICATION
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Remember
- correct term
- chapter link
- clear application
Examples
- Define first
- Show the rule or evidence
- Check units, labels, and conclusion
Remember
- Pythagoras again
- same centre
- outer chord tangent to inner
- keep the ideas separate
- Pythagoras again
- same centre
- outer chord tangent to inner
- correct term
Deeper understanding
Go beyond memorising Number. Connect the definition to reasons, relationships, exceptions, and exam wording.
Common mistakes
Exam focus
Core Idea
Key Points
Simple Check
How to Answer
Exam focus
Quick revision
- Pythagoras again
- same centre
- outer chord tangent to inner
- keep the ideas separate
- Number: R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
- WHAT — NUMBER: R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
Do not merge number with a neighbouring idea that uses a different definition, rule, or method.
For long answers on Number: define clearly → explain the main parts → give one example → state one exam caution.
Exam Focus
Exam Focus
Important points
- Pythagoras again
- same centre
- outer chord tangent to inner
- keep the ideas separate
Important formulas
- Pythagoras again
- same centre
- outer chord tangent to inner
Common exam traps
- Do not merge number with a neighbouring idea that uses a different definition, rule, or method.
- Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
Long question structure
Definition → key parts → example → exam caution
Common Mistakes
Common Mistakes
- Mistake
Do not merge number with a neighbouring idea that uses a different definition, rule, or method.
- Mistake
Do not invent a formula, fact, unit, or diagram label that the chapter does not support.
- Mistake
Do not merge number with a neighbouring idea that uses a different definition, rule, or method.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
Pythagoras again
same centre
outer chord tangent to inner
keep the ideas separate
R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
- Definition
- R=13, r=5: half-chord 12, chord 24. Same 5-12-13 triangle as chord-from-centre questions.
- Example
- Pythagoras again
- Critical warning
- Do not merge number with a neighbouring idea that uses a different definition, rule, or method.
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.
Ready to test yourself?
You've completed the learning section.
Exam Practice
Define
Q1. Define Number.
Explain
Q2. Explain: CORE UNDERSTANDING.
Example
Q3. Give one clear example of Number and say why it fits.
Mistake
Q4. State one common mistake students make about Number.
Exam note
Q5. Write a short exam note on Number: definition, two points, one example.
Sources & References
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.