<p>I believe the correct answer is (D).</p>
<p>If you assign values of 6, 8, and 10 to the triangle, then the sum of the areas of the half triangles add to 25pi divided by 2.</p>
<p>Given these assigned numbers, the hypotenuse is 1. Answer choice (D) is equal to 100pi divided by 8, which reduces to 25pi divided by 2.</p>