Tangents are equal

OBJECTIVE

To verify that lengths of tangents drawn from an external point to a circle are equal.

PREREQUISITE KNOWLEDGE

Meaning of tangent to a circle

MATERIALS REQUIRED

Coloured glazed paper

Chat paper

Colours

Scissors

Geometry box

Fevicol

PROCEDURE

Cut a circle from glazed paper of any radius with centre O.

Paste the cut-out of a circle on the chart paper

Take any point P outside the circle ( Image 1)

                                                                          Image 1

Place a ruler touching the point P and circle at the point A  and fold along the crease to get the tangent as AP

Place a ruler touchings the point P and circle at the other point B  and fold along the crease to get the other tangent as BP

Join OA,OB and OP ( Image 2)

                                                                           Image 2

Fold the circle along Op ( Image 3)

                                                                             Image3

OBSERVATION

We observe that point A coincides with point B

CONCLUSION

 Lengths of tangents drawn from an external point to a circle are equal.