Question

Knowing that sin 30 = 1/2 what is a

Answer 1

$sin30^o=\frac{9}{a}\\\frac{9}{a}=\frac{1}{2}\\a=2\cdot9\\a=18$

Answer 2

Answer:

B. 18  

Step-by-step explanation:

We have been given a diagram of a right triangle and we are asked to find the value of a.

Since we know that Sine relates the opposite with hypotenuse of a right triangle.  

$\text{sin}=\frac{\text{Opposite}}{\text{Hypotenuse}}$

Upon substituting our given values we will get,

$sin(30^o)=\frac{9}{a}$

Upon substituting $sin(30^o)=\frac{1}{2}$ in above equation we will get,

$\frac{1}{2}=\frac{9}{a}$

Now let us cross multiply our equation to solve for a.

$1\cdot a=9\cdot 2$

$a=18$

Therefore, the value of a is 18 and option B is the correct choice.