Ruler and Compass Construction 31B
Internal Tangents to Two Given Circles

Reset
1. Ray AB
2. Perpendiculars to AB at A and B
3. Top and bottom of circles C, D
4. Ray CD; intersection E
5. Midpoint F of AE
6. Circle centered at F through A
7. Points of tangency G, H
8. Tangent lines EG, EH
Explanation of the construction: Steps 1-4 find the point E, the concurrent point of all lines passing through corresponding points of the two circles. The desired tangent lines must also pass through E. Then it is construction 27 to find the tangent lines.
Back to constructions page
Next construction: 32 Circle Tangent to Parallel Lines and Circle
Previous construction: 31A Circle Outer Tangents
Susquehanna University assumes no responsibility for the content of this personal website. Please read the disclaimer.