# Circle Investigations

Author:
bsharp67
Topic:
Circle

## Investigation 1.

1. Grab point B. Move it around. What can you say about line CB? 2. What type of segment is AB? 3. Move B around. What do you notice about the angle measure of CBA? 4. Make a conjecture about what happens when a radius and a tangent line meet at the same point.

## Investigation 2

1. Grad D and move it around. Grab F and move it around. What type of lines are GD and GF? 2. What do you notice about the measurements of segments DG and FG? 3. Move D and E. What happens to the segment measurements? 4. Make a conjecture about the length of segments the lie on tangent lines and have a common point exterior to the circle.

## Investigation 3

1. What type of angle is angle CAB? 2. What type of angle is angle CDB? 3. What do these two angles have in common? 4. Move point C. What do you notice about the relative size of angles CAB anf CDB? 5. Make a conjecture about the relative sizes of a central angle and an inscribed angle that subtends the same arc on a circle.