Question

Knowing that sin 30 = 1/2 what is a

Answer 1

`sin30^o=(9)/(a)\\(9)/(a)=(1)/(2)\\a=2\cdot9\\a=18`

Answer 2

B. 18

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)=(9)/(a)`

Upon substituting
`sin(30^o)=(1)/(2)` in above equation we will get,

`(1)/(2)=(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.