Left = (width)(height of each rectangle)

$\text{Left} =(0.5)(\sqrt{3+2}^2+\sqrt{3.5+2}^2+\sqrt{4+2}^2+\sqrt{4.5+2}^2$

$f(x_{0})\ \ \ \ \ \ \ \ \ f(x_{1})\ \ \ \ \ \ \ \ f(x_{2})\ \ \ \ \ \ \ f(x_{3})$

Right = (width)(height of each rectangle)

$\text{Right} =(0.5)(\sqrt{3.5+2}^2+\sqrt{4+2}^2+\sqrt{4.5+2}^2+\sqrt{5+2}^2$

$f(x_{1})\ \ \ \ \ \ \ \ f(x_{2})\ \ \ \ \ \ \ f(x_{3})\ \ \ \ \ \ \ \ \ f(x_{4})$

$\text{Left endpoints} =\displaystyle\sum\limits_{k=0}^30.5\sqrt{(3+0.5k)^2+2}$

What modification results in the right endpoints?