add six nodes A-F
make node D a rectangle twice as wide as high
give node A a LaTeX label of \Theta
set the label offset for node A to be 1 units to the north west
give node B a LaTeX label of \chi^2(\alpha)
give node C a LaTeX label of x_0^3
give node D a LaTeX label of \int_0^\infty f(x) \dd{x}
give node E a LaTeX label of \frac{1}{2}
give node F a LaTeX label of \sqrt{\pi \cdot \frac{1}{2}}
set node size for node F to be 1.5, B to be 1.25, node D to be 1.4
set font color for node A to be steelblue
A is a parent of B through F