I was solving quant question from big book and was unclear with this answer of this problem. From the given data, there were two combination: (40+40+100) and (70+70+40). And only (70+70+40) could form a isosceles triangle and other couldn’t according to triangle property( 40+40 < 100). So, I choose option A(70+70>120) as there was only one possible triangle and question clearly states “sum of the measures of two angle of triangle RST that have equal measure” but the answer was D. And, so was the answer in Greg’s quant walk through.
I got logic why they choose D (40+40<120 and 70+70>140). So, My question/confusion is, Do we need to consider if the given combination of angle form a proper triangle while solving problem?
