STEM Excellence Series: Empowering the Next Generation

TANGENT

Tangent

Definition Of Tangent

A tangent to a curve at a point is a straight line that touches the curve at that point.

Examples of Tangent

The line AB is a tangent to the circle at P.

A tangent line to a circle contains exactly one point of the circle
A tangent to a circle is at right angles to the radius of the circle at its point of contact

Video Examples: Tangents and Circles

Solved Example on Tangent

Ques: Find the number of tangents that can be drawn from a point inside a circle to the circle.

Choices:

A. 1
B. 2
C. infinite
D. 0
Correct Answer: D

Solution:

Step 1: No tangent can be drawn from a point inside a circle to it.

Quick Summary

  • A tangent line touches a circle at exactly one point.
  • A tangent to a circle is at right angles to the radius of the circle at its point of contact.
  • No tangent can be drawn from a point inside a circle to the circle.
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🍎 Teacher Insights

Use dynamic geometry software to demonstrate the relationship between the radius and tangent. Emphasize real-world applications such as wheels and axles.

🎓 Prerequisites

  • Circles
  • Lines
  • Angles
  • Radius
  • Diameter

Check Your Knowledge

Q1: How many tangents can be drawn from a point inside a circle to the circle?

Q2: A line touches a circle at one point. Is it always a tangent?

Frequently Asked Questions

Q: Can a tangent line intersect the circle at more than one point?
A: No, a tangent line intersects the circle at exactly one point.

Q: Is a tangent line always perpendicular to the radius at the point of tangency?
A: Yes, a tangent line is always perpendicular to the radius drawn to the point of tangency.

Q: How many tangents can be drawn from an external point to a circle?
A: Two tangents can be drawn from an external point to a circle, and these tangents are equal in length from the external point to the points of tangency.

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