AP EAMCET202023 Sep 2020Morning ShiftMathematicsProperties of TrianglesActual
Let a , b and c be the lengths of the sides of a triangle with its opposite angles A , B and C respectively. If a = 3 , b = 4 and A = sin - 1 3 4 , then the angle B is
Options
- A30 °
- B45 °
- C90 °
- D60 °
Correct answer
C. 90 °
Step-by-step solution
Given, a = 3 b = 4 and A = sin - 1 ( 3 4 ) ⇒ sin A = 3 4 Using sine rule, we get a S i n A =   b sin B ⇒   sin B = b sin A a ⇒ sin B = 4 × 3 4 3 ⇒ sin   B = 1 ⇒ B =   sin - 1   ( 1 ) ⇒ B = 90 ° .