Tangents to a circle

Objectives

To understand what is a tangent and its relationship to the circle

Estimated Time

30 minutes

Materials/ Resources needed

Click here to open the file

Process (How to do the activity)

Download this geogebra file from this link.

Procedure:

1. O is the center of the circle and tangents AP and AQ are drawn from an external point A.
2. OP and OQ are the radii.
3. The radii of a circle are equal.
   1. In any circle the radius drawn at the point of contact is perpendicular to the tangent.∠BDA=∠BEA=90
   2. We can draw two tangents to a circle from a point outside the circle
   3. The lengths of the tangents from a point to a circle are equal BD=BE
   4. The tangent drawn from an external point to a circle a] are equal b] subtend equal angle at the centre c] are equally inclined to the line joining the centre and extrnal point.
   5. Angle between the two tangents from a point outside the circle is supplementary to the angle subtended by the line segmnets joining points of contact at the cente
   6. Properties of isoscles triangle.
   7. Properties of quadrillateral ( sum of all angles) is 360 degrees
   8. Sum of three angles of triangle is 180 degrees.

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