http://www.ck12.org Chapter 9. Circles
If the circles are not tangent, they can share a tangent line, called acommontangent. Common tangents can be
internally tangent and externally tangent too. Notice that the common internal tangent passes through the space
between the two circles. Common external tangents stay on the top or bottom of both circles.
Concentric Circles:Two or more circles that have the same center, but different radii.
Congruent Circles:Two or more circles with the same radius, but different centers.
Example A
Find the parts of
⊙
Athat best fit each description.
a) A radius
b) A chord
c) A tangent line
d) A point of tangency
e) A diameter
f) A secant
Answers:
a)HAorAF