Problem:
Two angles of an isosceles triangle measure and . What is the sum of the three possible values of
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The two angles measuring and , in an isosceles triangle, could be positioned in three ways, as shown.
If and are the degree measures of the congruent angles, then . If is the degree measure of the vertex, then is . If is the degree measure of one of the base angles, but not , then is . The possible values of are and . The sum of these values is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions