15 points+ brainliest please i need it asap

Step-by-step explanation:

Since 9^2 + 12^2 = 15^2, it can form a right-angled triangle.

Since 2^6 + 6^2 = 40 and 40 ≠ (√38)^2, it cannot form a right-angled triangle.

Since 3^2 + 9^2 = 90 and 90 ≠ (√91)^2, it cannot form a right-angled triangle.

So the only answer is A.

The median of any trapezoid has two properties: (1) It is parallel to both bases. (2) Its length equals half the sum of the base lengths.

Step-by-step explanation:  So there were not any choices but the sentence above states the true properties of the median of a trapezoid.  

I hope I helped :)