Can you help with this, I don't know how to do it

105 sqrt(2) =x

Step-by-step explanation:

Since this is a right triangle we can use trig functions

so  sin theta = opposite side/hypotenuse

    sin 45 = x/210

Multiply each side by 210

210 sin 45 = x

We know sin 45 = sqrt(2)/2

210 * sqrt(2)/2 = x

105 sqrt(2) =x

B

Step-by-step explanation:

Using trig ratios

sin(45) = opposite/hypotenuse

sin(45) = x/210

sqrt(2)/2 = x/210

x = 210sqrt(2)/2

x = 105sqrt(2)

21/58.

hope to be marked brainliest