[Graphs generated by this script: setBorder(35,35,75,35);initPicture(0,15,0,15);path([[0,0],[15,0],[0,15],[0,0]]);path([[0,1],[1,1],[1,0]]);text([15/2,0],"15","below");text([0,15+.5],"<-- 45°","right");text([15+.5,0],"<-- 45°","right");text([0,15/2],"15","left")]

What is the best name for the figure above?



What is the length of the hypotenuse?  

152\displaystyle {15}\cdot\sqrt{{{2}}} =