


Challenge 


Radius:
The distance from the center of a circle to any point on the circle. Also, the line segment that has the center of the circle as one endpoint and a point on the circle as the other endpoint. 
Tangential Circles: Compare the area and circumference of a circle inscribed in a region between two intersecting circles.
Equal Areas: Construct a circle with five equal regions that do not intersect at the circle's center.
Tangent Along the Diameter: Find the relationship between the area of a circle and the areas of the tangent circles along the circle's diameter.
Changes in the Circumference: Explore how changing the diameter of a circle affects its circumference.
Area of a Sector: Determine the relationship between the area of a circle's sector and the radius and central angle of the circle, and between the arc length of a circle and the radius and central angle of the circle.


