Let the angles be A=x,B=2x,C=3x
⇒x+2x+3x=180o
⇒6x=180o
⇒x=30o
Therefore, A=1×30o=30o,
B=2×30o=60o
and C=3×30o=90o
Therefore, the smallest angle is 30o.
If the measures of angles of a triangle are in the ratio of 3 : 4 : 5, what is the measure of the smallest angle of the triangle?