¶ 1960 AHSME Problem 38
Problem: In this diagram and are the equal sides of an isosceles triangle , in which is inscribed equilateral triangle DEF. Designate angle BFD by a, angle ADE by , and angle FEC by . Then
Answer Choices:
A.
B.
C.
D.
E. none of these
Solution:
Since , we have b+c=2 a, a=\dfrac{b+c}