seeing as no one else has answered...

its evudentaly a three dimensinal shape because there are three figures.

z (to the second power) = x (to the second) + y (to the second)/4

4z (to the second) = 4x (to the second) + y (to the second)

the square root of y (to the second) = the square root of -4x (to the second + 4z (to the second)

my first instinct was that it was a cone. but i would go with a sphear.