The first one is No. The second one I do not know unfortunately.
Step-by-step explanation:
I am in the middle of this lesson in my math class as well and I know that in order to make a triangle, you need the two smaller sides to add up to become larger than the biggest side. In the case of the first question, the two smaller sides, 6 and 3 equal 9, which is not bigger than the biggest side which is 10. I hope you can find the answer to the second one, but for now, the first one is No.
If we want to find the distance between two points in a coordinate plane we use a different formula that is based on the Pythagorean Theorem were (x1,y1) and (x2,y2) are the coordinates and d marks the distance