Tangents From An External Point

Theorem:

The tangents to a circle from an external point are equal.

ASSIGNMENT

1.O is the centre of a circle and two tangents from a point T touch the centre at A and B. BT is produced to C. If <AOT = 67⁰.calculate < ATC.

2.AD is a diameter of a circle,AB is a chord and AT is a tangent. a) State  the size of  <ADBb)If BAT is an acute angle of  x⁰,find  the  size  of DAB in terms of   x.