# The construction of a tangent to a cicle

For a lot of things in life, an approximation is good enough; you can just kind of eye ball it in. But that's not always the case, especially in manufactoring- you need to be precise. The circle, has been for centuries, a shape with a perceived great potential. Certainly, the wheel has revolutionized the way we travel-from cars and planes to even the space shuttle. We are going to use a computer software application called Geometer's Sketchpad to investigate how we could "construct" a tangent to a circle in the same essential way that we have traditionally done with a compass and a straight edge. Let's us begin

You see above and can manuver the circle with tangent line in many different ways. You can grab the tangent line and drag the circle around or you can snag the circle and move it or even change the radius (do so if you haven't already). Once you spent some time fooling around with the workable drawing, take some time to investigate Sketchpads' capabilities by going up to file and choosing new sketch.

By now you've had some fun and are ready to learn about the construction of a tangent. What you will be doing is following a script of the creation of a tangent line to a circle given a circle and a point outside the circle. You will be given an arbitruary circle and press "step" over on the script to watch how a tangent is constructed. continue

Now you should be ready to do it yourself! Go back up to file and select a new sketch and draw your own circle, point and go for it!

You've come a long way! Have a nice day