INTERNAL TANGENT

To construct an internal tangent to two equal circles.
1. O and C are center 25 mm of radius = 25 mm.
2. OC = 80 mm
3. Bisect OC at A.
4. Bisect OA at B.
5. With B as centre draw a semicircle on OA.
6. T is the point where the semicircle crosses circle O.
7. Join TA and produce to T1.
8. Then TAT1, is the required tangent.