Hello I have a doubt in in exercise 6.3 of maths NCERT book I have dought  in 6.3 there's is  question number 4 in question number 4 there was given that isosceles triangle so what we will do in that questions you will also giving solution in the app and download the app but in question number second of 6.3 it was given only 30 degree angle so we have taken like 90 degree angle and we have to take out the another angle then 50 question both xor given I cannot understand what was that thing you are just given in the solution of teacher app so can you please explain me short form