Equilateral triangle ABC is inscribed in circle O, whose radius is 4. Altitude BD is extended until it intersects the circle at E. What is the length of DE?

Question

a) √3

b) 2√3

c) 2

d) 4√3

Answer 1

The altitude of an equilateral triangle is also a median.

The medians intersect 2/3 of the way from the vertex to the opposite side.

So, BO=4, and BD=6

BE is the diameter of the circle, so BE=8

so, what do you think?