This calculation drives people to despair! how much has the farmer earned?

Puzzle
The puzzle itself is quite simple in design: it shows an image of a cow surrounded by

various geometric figures and asks participants to calculate a numerical value.

At first glance the solution seems direct and simple $400 but the way to this answer is

riddled with subtle mathematical pitfalls that many overlook.

Puzzle
The puzzle itself is quite simple in design: it shows an image of a cow surrounded by

various geometric figures and asks participants to calculate a numerical value.

At first glance the solution seems direct and simple $400 but the way to this answer is riddled with subtle mathematical pitfalls that many overlook.