KCET2008MathematicsProperties of Triangles
The angles A, B and C of a triangle A B C are in AP. If b : c = 3 : 2 , then the angle A is
Options
- A30^
- B15^
- C75^
- D45^
Correct answer
C. 75^
Step-by-step solution
Since A, B, C are in AP. B= A+C 2 B =90^ - B 2 ( A + B + C =180^ ) B =60^ Using sine rule, B b = C c 60^ 3 = C 2 3 2 3 = C 2 C= 1 2 aligned & C &=45^ A &=180^ - (60^ +45^ ) &=75^ aligned