Errata

The design graphic for the engraving (p. 53) says, "The two mountain triangles are the same shape, but rescaled/flipped." The hint is circled for emphasis on p. 61.

The example proceeds as if the triangles were not flipped.

The graphics were created as if they were flipped, and the example misses a useful connection to the discussion of similar triangles.

In other words, shouldn't the bottom left angle of the larger mountain be 53 degrees rather than 41?

The oversight propagates through half the chapter, through p. 76.

it is said on Chapter 2 - page 61 (designer's notes ) that both triangles are similar AND FLIPPED, so the angles shouldn't be flipped too?

I agree with my Anonymous friend errata :

"The design graphic for the engraving (p. 53) says, "The two mountain triangles are the same shape, but rescaled/flipped." The hint is circled for emphasis on p. 61.

The example proceeds as if the triangles were not flipped.

The graphics were created as if they were flipped, and the example misses a useful connection to the discussion of similar triangles.

In other words, shouldn't the bottom left angle of the larger mountain be 53 degrees rather than 41?

The oversight propagates through half the chapter, through p. 76."

In the cell you say to add the shortest side squared with the longest side squared. it should be shortest side squared with the middle side squared. Its correct in the solution but wrong in the question.