Question

The angles of a triangle are in AP such that the greatest angle is double the least,find the angles.

Answer 1

Let three angles be a-d ,a ,a+d
Their sum = a-d +a+a+d = 180 [When three terms are in AP then its taken as a-d,a ,a+d]
3a = 180
a =60
largest angle = 60+d
smallest = 60-d
Largest = 2(smallest)
60+d = 2(60-d)
60+d = 120-2d
3d = 120-60
3d = 60
d = 20
Angles are = 60+20 ,60 , 60-20
= 80 ,60 , 40