namratasingh wrote:Hi,
I didn't understand this part.
"BF = 1/2 BE & angle (BFE) = 90
=> the triangle is a 30-60-90 triangle , with angle(BEF) = 30 and angle(FBE) = 60 "
I understand sum of angles of Triangle is 180, but didn't get this one.
Also, I wanted to ask which are the Fundamentals to remember while solving problems related to Triangles?
Please help.
Hi namratasingh:
There are two special right angled triangles that the GMAT expects you to know.
First is the 30-60-90 triangle. In the 30-60-90 triangle, the sides opposites to the angles are in the ratio 1:sqrt(3):2. Any time you see a right angled triangle with two sides in 1:2, 1:sqrt(3), or 2:sqrt(3) ratio, you need to recognize if the triangle is 30-60-90.
The other special triangle is 45-45-60. In this one, the sides are in the ratio 1:1:sqrt(2). So anytime you see a right angled triangle in which sides are in the ratio 1:sqrt(2), you need to determine whether the triangle is 45-45-90.
Besides these two, there are some other right angled triangles, in which the computation is made easier if the sides are in a particular ratio.
a. 3:4:5 right angled triangle. (This may show up as 6:8:10 or 15:20:25 right angled triangle etc.)
b. 5:12:13 right angled triangle.(This may also show up as 10:24:26 right angled triangle etc.)
This is the bulk of it. Remembering this will help you immensely in triangle geometry questions.
Let me know if this helps
