If the angles of a triangle are in the ratio , then the ratio of the longest side to the perimeter is
- A.
- B.
- C.
- D.
Show answer and solution
Correct option: A
Solution
The angles are 4:1:1, summing to 180°, giving angles 120°, 30°, 30°.
By the sine rule, sides are proportional to sin(120°), sin(30°), sin(30°) = (√3/2), (1/2), (1/2).
Longest side : perimeter = (√3/2) : (√3/2 + 1/2 + 1/2) = √3 : (√3 + 2) = √3 : (2 + √3).
By the sine rule, sides are proportional to sin(120°), sin(30°), sin(30°) = (√3/2), (1/2), (1/2).
Longest side : perimeter = (√3/2) : (√3/2 + 1/2 + 1/2) = √3 : (√3 + 2) = √3 : (2 + √3).
[AIEEE 2003]