GSP Menu Page  MathBits Main Page
Tangents to a Circle
Stepbystep directions for constructing
tangents to a circle from a point
not on the circle
using Geometer's Sketchpad.

Construct a tangent to a circle from a point not on the circle. 
1. Use to draw a circle. Label it O. Right clicking
on a point will allow fast labeling if automatic
labeling it not turned on. To turn on Automatic
Labeling, choose Edit, Preferences, Text Tab, check the
box under Show Labels Automatically "For All New
Points".
2. Use to locate a point not on the circle. Label it P.
Does this really work? Are these really tangents?

GSP Menu Page  MathBits Main Page