Curious pyramid...the "Bent Pyramid"

Bent Pyramid at Dahshur Egypt

The lower part of the pyramid has an angle of 54° and the upper part is at 43°. Why is it bent?

1.) Time and/or money. Basically this idea says that they either didn’t have the time or money to finish the pyramid at the initial slope. To cut costs [or time] they changed the angle.

2.) Material failure. Building the pyramid at the original slope caused structural instabilities. Either the foundation couldn’t take the weight or the building material itself started to crack.

3.) Alien sense of humor.

Bent Pyramid [Wikipedia]

THE GEOMETRY OF THE BENT PYRAMID