position of right angle in a triangle

Question

In one of the questions that I solved, the stem reads as "In right angled triangle ABC ...."
My question is can we safely deduce from the stem that the triangle is right angled at B?

In my school we were taught that in a right angle triangle it is always the middle angle (as per the naming) that is a right triangle. is this information correct?

vishalbalwani · Answer

Do not assume it to be the case.
A triangle can be named as ABC, BCA,CAB but in all the cases the right angle, if any, might be at angle B.

Hence do not assume the position of the angle unless mentioned explicitly.

abhimahna · Answer

Hi klrahul ,

No, this is not allowed. If you are given a figure that displays angle B as right, then it's fine. If not, you cannot assume angle B is right angled. You must have the information "right angled at B".

Unfortunately, what you read in school is wrong.

Good luck

Bunuel · Answer

If it's given that triangle ABC is right you CANNOT assume that B is a right angle, it might as well be A or C.

Nikkb · Answer

klrahul

I agree, in general math practice we follow naming conventions for proper understanding. Like if given angle ABC =30, we know angle at B is 30, or if triangle ABC ~ triangle DEF, we conclude angle A = angle D and so on. We have to follow such rules while providing detailed solution for questions.

But in GMAT questions, until and unless questions specify a particular angle or give you an figures with angles marked on it, don't go purely on naming conventions.

position of right angle in a triangle

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