Tangent of Circle

Instruction: Construct a tangent to the circle from the external point.

Goal: 4L 5E 2V

Available Tools:

• Move
• Point
• Line
• Circle
• Perpendicular Bisector
• Perpendicular
• Angle Bisector
• Parallel
• Non-collapsing Compass
• Intersect

Pack: Kappa

Previous Level: 9.10

Next Level: 10.2

4L Solution

Let A be the center and B the given point.

1. Construct line AB.
2. Construct the perpendicular bisector of AB, intersecting AB at C.
3. Construct circle C with radius AC, intersecting circle A at D.
4. Construct line BD.

5E Solution

Let A be the center and B the given point.

1. Construct line AB, intersecting circle A at C.
2. Construct circle C with radius BC, intersecting AB at D.
3. Construct circle A with radius AB, intersecting AB at E.
4. Construct circle E with radius DE, intersecting the latest circle at F.
5. Construct line BF.

2V Solution

From the 4L Solution

1. Let the other intersection between circle A and circle C be E.
2. Construct line BE.

From the 5E Solution

1. Let the other intersection between circle E and circle A be G
2. Construct line BG.