Gmat language in representing geometry figures

Question

hi

I had a doubt while attempting a geometry question. If it is mentioned that triangle ABC is a right angle triangle, cant we assume that angle B is 90. Isnt that a standard usage?

Also, if Triangle MNP is a isosceles triangle can we assume that MN= NP.

I remember being taught in school that these are the ways in which we denote such figures, but will gmat specifically mention these. eg that if (tr)ABC is a rigth angle triangle then angle b is 90.

thanks

EvaJager · Answer

I doubt any such convention being followed on the GMAT. Sometimes, a drawing is attached and the right angle marked. There might be additional info from which you can deduce which one is the right angle. Similar for an isosceles triangle.

Just for curiosity: did you learn in a European school?

premnath · Answer

For all geometry questions, you don't necessarily need to consider B as 90 degree, unless otherwise it is specifically mentioned in the question.
You can assume any one of A,B,C as 90 degree and solve the problem. Only requirement is that the side opposite to right angle is the hypotenuse.

If B is 90 degree, then  a^2 + c^2 = b^2 
If A is 90 degree, then  b^2 + c^2= a^2 
If C is 90 degree, then  a^2 + b^2 =c^2

where a,b, and c are sides opposite to angle A,B, and C respectively.

Gmat language in representing geometry figures

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