Instructions:
In Geogebra or using a compass and ruler complete these steps:
Step 1: Open Geogebra
Step 2: Draw a Circle
Use the circle tool to create a circle and label the center as O.
Step 3: Place a Point on the Circle
Select a point P anywhere on the circle.
Step 4: Construct the radius
Between points 0 and P, construct radius OP
Step 5: Construct a tangent line
Construct a line that touches the edge of the circle but does not cross the circle using the line tool. The second point will be placed outside the circle.
Label the line t.
Step 6: Measure the Angle
Measure the angle between the radius OP and the tangent t.
Record your result.
Step 7: Investigate
Zoom in and see if the line is touching the circle in only one place.
If it is, what is the angle measurement?
If it is not, move the line until it touches the circle only in one spot.
Make new points and tangent lines if necessary.
Discussion Questions:
What do you notice about the angle between the radius and the tangent each time?
Do you think this is always true? Why?
Fill in the students notes for 9.6 Tangent Lines while watching the video.
We will work through Goal #1 together.
These words will be filled in on your student notes.
Tangent Line - the straight line that "just touches" the curve at that point
Point of Tangency - the specific point where a tangent line touches a curve without intersecting it.
As a class, we will work through Goal #2 and Property 4 lass Examples 1, 2, and 3.
Your task is to complete Property 4 Partner Example Exit Slip.