Tan is the right answer
hope it helps you ❣❣
<h2>Mark me as brainliest </h2>
Simple...
you have:

To make this into an improper fraction-->>
1.) Multiply whole number by denominator
2.)Add the number you got plus the numerator
3.) Use the original denominator to finish your improper fraction
Example:

4*9=36
36+4=40

Thus, your answer.
To find the area of a circle, you do π × diameter (in this case 10). They have told you to use 3.142 as π, so you do 3.142 × 10 = 31.42. Because it's a semi-circle, you need to halve 31.42 to get 16.21, which is the answer