Triangle qrs has the angle measures shown.
m∠q = (1x)°
m∠r = (3x)°
m∠s = (6x)°
the measure of the obtuse angle equals?

We know that the sum of measures of angles of a triangle is equal 180 degrees 

in this case we can writing 180 = m<Q +m<R + m<S  so 

180 = 1x + 3x +6x

180 = 10x 

x = 18

in this way we can calcule that the measure of obtuse angle
m<S = (6x)° = 6*18 = 108 degrees