The angle of triangle are in A.P. Given, smallest angle is 50∘ less than largest angle. We know that, I=a+(n−1)d Here, let a= first smallest angle is x. I= largest angle =x+50 and n=3 (angle) ⇒50+x=x+(3−1)d ⇒50+x=x+2d ⇒2d=50 ⇒d=25 The distance between all 3 angle is 25. Sum of all 3 triangle is 180∘. Then, a+2 nd angle +1=180∘ ⇒x+x+25+x+50=180∘ ⇒3x+75=180∘ ⇒3x=105∘ ⇒x=35∘ ∴ Largest angle I=x+50∘ =35∘+50∘=85∘