Answer: Line TM drawn through M with ∠NMT = ∠MKN is the required tangent.
Steps of construction:
- Draw a circle of radius 3.6 cm and take a point M on it.
- Draw any chord MN through M.
- Take a point K on the major arc MN, other than M and N. Join KM and KN to form ∠MKN.
- With K as centre and a convenient radius, draw an arc cutting seg KM at P and seg KN at Q.
- With M as centre and the same radius, draw an arc cutting chord MN at R and extending to the side of chord MN opposite to point K.
- With R as centre and radius equal to PQ, draw an arc cutting the previous arc at T, on the side of chord MN opposite to point K. Then ∠NMT = ∠MKN.
- Draw line MT.
- Line TM is the required tangent to the circle at M.
Reason: By the converse of the tangent-secant angle theorem, if the angle between a line and a chord at a point of the circle equals the inscribed angle on the other side of the chord, the line is a tangent at that point.