MathematicsChapter 10: Tangents and Angles of a Circle
Definition and 90 Deg
From a point on the circle, exactly one tangent.
Learning objectives
- Define and explain definition and 90 deg.
- Apply definition and 90 deg to a focused FBISE question.
- Check the answer for correct terms, evidence, working, and units.
Definition
From a point on the circle, exactly one tangent. The radius is the perp from O to the tangent, so it is the shortest path from O to the line.
Where / symbols
- Definition And 90 Deg
- From a point on the circle, exactly one tangent. The radius is the perp from O to the tangent, so it is the shortest path from O to the line.
Overview
Learn the idea, then use it:
Core Understanding
From a point on the circle, exactly one tangent. The radius is the perp from O to the tangent, so it is the shortest path from O to the line.
Examples one point of contact · touches at one point · radius perp tangent · DEFINITION AND 90 DEG: From a point on the circle, exactly one tangent. The radius is the perp from O to the tangent, so it is the shortest pat
Exam Application
State the correct term, connect it to the chapter rule or evidence, and use a clear example or calculation.
Examples Define first · Show the rule or evidence · Check units, labels, and conclusion
WHAT — DEFINITION AND 90 DEG
From a point on the circle, exactly one tangent. The radius is the perp from O to the tangent, so it is the shortest path from O to the line.
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.
In simple words
Do not merge definition and 90 deg with a neighbouring idea that uses a different definition, rule, or method.
Key points
- one point of contact
- touches at one point
- radius perp tangent
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Definition and 90 Deg
Sticky Notes · Quick Revision
Core Idea
- From a point on the circle, exactly one tangent.
Key Points
- one point of contact
- touches at one point
- radius perp tangent
Simple Check
- Explain definition and 90 deg in your own words and connect it to one chapter example.
How to Answer
- Define the idea, show the main rule or evidence, apply it, and check the final statement.
Common Mistake
- Do not merge definition and 90 deg with a neighbouring idea that uses a different definition, rule, or method.
FBISE Exam Tip
- Use the exact term, show working where needed, and include units or labelled evidence.
60-second revision
- From a point on the circle, exactly one tangent.
- one point of contact
- touches at one point
- radius perp tangent
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