In ΔABC, if the ratio of angles are in the proportion 3 : 5 : 4, then the difference between the biggest and the smallest angles (in degrees) is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 30o
Let the angles be 3x, 5x & 4x in ΔABC.
The sum of all the angles in a triangle is 180°
⇒ 3x + 5x + 4x = 180°
⇒ 12x = 180°
⇒ x = 15°
The difference between the biggest and smallest angle is (5x - 3x) is 2x.
⇒ 2x = 2 × 15°
⇒ 30°