Problem :
Explain why all radii of a circle are congruent.
A radius has one endpoint on the center and one on the circle. All
points on the circle, by
definition, are equidistant from the center, so no matter which point on the
circle is the
endpoint of a given radius, it is
congruent to
any other radius.
Problem :
If the radius of circle P is the same length as the diameter of circle M, how
long is the
diameter of circle P in terms of r, the radius of circle M?
The diameter of circle P equals
4r, where
r is the radius of circle M.
