In △ABC, if the ratio of angles is in the proportion 3 : 5 : 4, then the difference between the biggest and the smallest angles (in degrees) is:
Answer & explanation
Correct answer: option 4
Total sum of angles in a triangle = 180°
Here, the proportion of angles = 3 : 5 : 4
Thus, 12r = 180°
r = 15
Biggest angle = 5r = 5 x 15 = 75°
Smallest angle = 3r = 3 x 15 = 45°
Difference between them = 75 - 45 = 30°