2015 · Q69
A B C is a triangle right angled at B and A B : B C = 3 : 4. What is A+ B+ C equal to?
Elementary MathematicsTrigonometry
- A2
- B11/5
- C12/5
- D3
Explanation
Reading the question as sin²A + sin²B + sin²C (same notation as Q75) with legs AB:BC = 3:4 and hypotenuse 5: sinA = 4/5, sinB = 1, sinC = 3/5, so the sum is 16/25 + 1 + 9/25 = 2 (option A).