Answer:
A. 16.55
Step-by-step explanation:
What we know is the angle of 38° and the hypotenuse is 21. Before we find x (side b), we have to find side a first. TO find that multiply the sine of 38 by 21.
21 * sin(38)
<em>sin(38) calculates to 0.615661475.</em>
21 * 0.615661475
<em>Multiply 21 by 0.615661475</em>
side a = 12.928890975
Now to find x. Use this to find x: √21² - 12.928890975²
√21² - 12.928890975²
<em>Square both numbers</em>
√441 - 167.156221843
<em>Subtract 167.156221843 from 441</em>
√273.843778157
<em>Find the square root of 273.843778157</em>
x ≈ 16.548225831
x ≈ 16.55, so the answer is A.