The picture below illustrates a special type of conic section called a circle. Which of the following offers the best description of how a circle is formed?

A. The plane passes through only one nappe of a right circular cone
and is perpendicular to its base.
B. The plane passes through the vertex of a right circular cone.
C. The plane passes through only one nappe of a right circular cone
and is parallel to its base.
D. The plane passes through both nappes of a right circular cone and
is perpendicular to its base.

Which of the following would be a correct step in proving that triangle abc is congruent to triangle cda? a. use a protractor to measure the angles and show that all the corresponding angles are equal in measure. this will allow you to prove congruence by aaa. b. show that segment ab is parallel to segment cd and segment ad is parallel to segment cb. this will allow you to prove congruency by asa. c. show that is segment ab is perpendicular to segment ad. this will allow you to prove congruence by sas. d. none of the above.