Most journalists don’t tend to think along mathematical lines.

It’s the “right brain” thing that makes us decent writers, but not, thankfully, designers of bridges or nuclear power plants.

So I was surprised when an old geometry lesson on concentric circles came to mind in connection with a Better Government Association investigation.

For math-challenged readers, concentric circles are “circles within circles” that share a center point.

The image — a dot ringed by a series of circles — seems to perfectly illustrate a corruption story in Lyons Township, where a tiny government agency called the Lyons Township School Treasurer’s office manages and invests 200 million tax dollars for more than a dozen west suburban school districts, including La Grange, Western Springs and Willow Springs.

For 20-plus years a politically connected bureaucrat named Robert Healy ruled supreme. He was the appointed treasurer — technically reporting to an elected, three-member board — but in reality doing what he wanted.

And what he wanted was to pocket money he wasn’t entitled to, according to the Cook County prosecutors who recently charged him with two felonies for allegedly embezzling more than $1.5 million over the years.

The criminal investigation followed a BGA probe that identified egregious and possibly illegal practices at the agency: Healy approving investments that may have violated state law, and accepting campaign cash from outside investment advisors.

Healy had no apparent financial expertise, but good connections, including political “godfather” Morgan Finley, a graduate of the Daley political organization and one-time Cook County official who engineered Healy’s appointment to the school treasurer’s office before going to jail for corruption.

One of the more shocking revelations about Healy: He didn’t keep a budget.

More than 200 million tax dollars coming in and going out for expenses, consultants and salaries, but no annual spending plan?

Read more: Ex-School Official Faces Detention

Insane.

So who’s to blame?

Enter the concentric circles.

Let’s say the center point represents the general public — the folks who always get screwed by the scammers.

The surrounding circles represent various layers of culpability, with Healy obviously filling the innermost orb because of his alleged malfeasance.

The next ring is for the treasurer’s office trustees who were elected to supervise Healy but apparently missed the memo.

They let him run amok, and so far they haven’t been held accountable.

In fact, amid the scandalous revelations, one was even elected a Cook County judge.

And where were the accountants in charge of the books? One is a longtime Healy associate who signed off on the financials, claiming everything was swell. Another circle.

Add a circle for the office’s attorney, who, as far as we can tell, didn’t raise any red flags and is still on the payroll, collecting generous fees.

The next ring represents school districts that paid little or no attention to how their money was being handled by Healy.

And finally, district taxpayers deserve their own circle — the outermost ring — for failing to show up at the school treasurer’s public meetings or ask the right questions.

It adds up to a lot of misconduct, ineptitude and squandered money that should have been used to educate students.

But it wasn’t, because the grownups in charge were running around in circles.

And even someone with right-brain tendencies can figure that one out.

Andy Shaw is President & CEO of the Better Government Association. Email ashaw@bettergov.org.Twitter @andyshawbga.