Special Triangles - Need to know?

[valkener]

Hey,

 

Do I need to know these rules for special triangles?

 

90-45-45

 

Sides Ratio

Isosceles: x : x : x

 

90-60-30

 

Sides Ratio

x : x : 2 x

[iowaguy]

Yes, absolutely!  You also need to know the 3,4,5 right triangle and the 5, 12, 13 right triangle.

[Brent@GreenlightGRE]

I'll also add that the formula for the area of an equilateral triangle sometimes comes in handy. 

If the length of each side is L, then the area is:

sqrt3(L^2)/4

 

Cheers,

Brent

[alf10087]

Yes. Learn them up to the point that they are basically automatic to you.

[Queen of Kale]

I think these triangles, plus the basic probability (combinations and permutations), will get you through at least half the problems and almost all of the difficult ones.

[Brent@GreenlightGRE]

I think these triangles, plus the basic probability (combinations and permutations), will get you through at least half the problems and almost all of the difficult ones.

I think "half" might be a bit of a stretch   

The test-makers are more interested in evaluating one's competency regarding real-life topics such as statistics, percent, and number sense. 

 

Cheers, 

Brent

[soporific]

I think "half" might be a bit of a stretch   

The test-makers are more interested in evaluating one's competency regarding real-life topics such as statistics, percent, and number sense. 

 

Cheers, 

Brent

I was lucky - I'd enrolled in Stats 2.1x on edx to upgrade my statistics literacy before doing research this summer. I took the GRE today without much preparation, and the 3 lectures (the online course just started) helped me tremendously with means, medians, etc.!

[Guest |||]

Yes, there are one or two questions on triangles on most exams it would seem.