Red Tuxer was kind enough to post a very interesting problem with triangles. I liked it so much that I’m translating it, so everyone can enjoy solving it. Here it goes…
[ABCD] is a square. [BCE] is a equilateral triangle. What you have to find out is the amplitude of the EÂD angle.
Pre-requisites: basic algebra and geometry.
Post your answers and explanations.
Última actualização: 08/06/2012
Partilhe:
75…
You just need to start with the ABC angle (90) of
the square and estimate the ABE angle.
Then, as both distances AB and BE are
equal, you have the answer.
Nice challenge !
I did not want to spoil the answer…75 is the angle
EAB…
Sergio has given quite a great clue guys. Why don’t you follow up?
EBC = 60º (180/30)
EBA = 30º (90 – EBC)
[AB] = [BE] => BÂE = BÊA = (180-EBA)÷2 = 75
EÂD = 90-EAB = 15
Answer: EÂD = 15º
Right on João! 🙂