Al Bità's Reviews > The Bedside Book of Geometry

The Bedside Book of Geometry by Mike Askew
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M_50x66
's review
Mar 12, 12

Read in January, 2012

This is the most disappointing of the four 'Bedside' books published by Pier 9/Quid Publishing. It looks the same as the others, but there is something essentially 'wrong' about it all.

The writing is not clear (it appears to be derives from several translations of various related subjects, and there appears to be little if any proofreading involved (the exercise on pp. 98-99 is just one example: within the problem setting, 'walks dues south' (instead of 'walks due south') and twice using 'turning left through a right angle' when 'turning left ninety degrees' would have been clearer; the 'Problem' then has a 'Method' section, and a 'The Solution' section, the only trouble being that the Solution section doesn't contain the solution at all, but a reference to non-Euclidean geometry, while the solution is provided in the very first section of the Method section!); and, as here. sometimes the approach is childish, asking questions such as a child might ask), some examples are obfuscatory (e.g. the box on page 133 on Catalan Numbers is as clear as mud! and the Pappus' Hexagon Theorem box on p 143 gets more confusing the more you think about it (if you transplant tree B so that it lines us with y and E, then surely it no longer lines up with x and D, nor with z and F…), the historical vignettes surprisingly trite and meaningless in relation to the topic… I kept on getting the impression that this was a quick cut-and-paste job pushed by the publishers.

Worst of all, however, is that the book contains indefensible errors.

On page 23, column 1, the authors refer to phi (the Golden Ratio = (1+√5)/2 = 1.61803…) but incorrectly equate this to x (referring to the figure above in its column). From the figure, it is obvious that the value of x must be less than 1, yet their equation makes it equal to phi (i.e. greater than 1)! The 'Solution' in the next column, therefore, is ridiculously incorrect!

Later, checking up on the section on the Golden Ratio (pp.64-65), there are more sloppy/incorrect entries: in the second column on page 64 the authors describe a rectangle as having a shorter side (=1) and a longer side = x) and then say that if we 'cut off' a square of 1 unit from the rectangle, the remainder has a ratio of (1 - x): 1 — this should be (x - 1): 1 — and this mistake is perpetuated in the following equations, ending with the equation: 'x squared' = x - 1 (when it should be: 'x squared' = x + 1). As a result, the mistake is carried on into the first sentence in the first column on page 65, which reads: "The value of x that makes 'x squared' equal to x - 1 is approximately 1.618 (you can check this with a calculator — squaring 1.618 results in 2.618, just 1 more than 1.618)." Here again, the x - 1 should be x + 1.
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