Could a translation error lead to squares to not be considered as rectangles?


I'm reading a certain set of kindergarten/lower primary maths textbooks that
is written by North American authors for an Asian company.

Whenever students are asked to identify the number of rectangles in a given
picture, the answer booklet gives the number of oblongs instead of the number
of rectangles.

While the topic may be too advanced for kindergarten students, the maths
textbooks indeed explicitly say at the bottom of the first page of a textbook
at the very first level to tell students that squares are special types of
rectangles, where levels 1-4 are for kindergarten students.

Additionally, the accompany guide for teachers devotes a whole page of
discussion as to how to teach that squares are special types of rectangles.
There's even a paragraph about teaching to kindergarten students. The
authors/some of the co-authors of the teacher guides are also authors/co-
authors of the textbooks. They have also said that if students are taught that
squares are not rectangles, then they will have misconceptions later.

Perhaps, the ones who wrote the answer booklets were not fluent in English
while the ones who wrote the textbooks were.

For example

> [picture with 4 circles, 2 triangles, 3 square rectangles, 2 oblong
> rectangles for a total of 5 rectangles]
>
> Circle ___
>
> Triangle ___
>
> Square ___
>
> Rectangle ___

The answer key would give only the numbers:

> 4
>
> 2
>
> 3
>
> 2

So, the last line is wrong since it should be 5.

Could this happen in Japanese? Or a Japanese dialect? I mean, is there
something specific about the translations of any of the following words
'rectangle, square, oblong, quadrilateral, quadrangle, parallelogram,
trapezoid/trapezium, rhombus' that would cause such confusion? I guess the
translator/s thought that when English speakers say 'rectangle', it means
'oblong in their language/dialect, but I don't see that as specifically a
problem for this particular language.

By the way, are squares considered rectangles in Japan? Apparently, these
things can vary by state, curricula, culture, time, etc. Please provide a
document from the education department of your government or something.

P.S. I'm a monolinguist.

Related:

[In Korea, are squares considered
rectangles?](https://korean.stackexchange.com/questions/3394/in-korea-are-
squares-considered-rectangles)

[Are kindergartners supposed to be steered from squares being
rectangles?](https://matheducators.stackexchange.com/questions/13831/)

[In what curricula are “rectangles” defined so as to exclude
squares?](https://matheducators.stackexchange.com/questions/13700/in-what-
curricula-are-rectangles-defined-so-as-to-exclude-squares)

[Why do we have circles for ellipses, squares for rectangles but nothing for
triangles?](https://math.stackexchange.com/questions/2249741/why-do-we-have-
circles-for-ellipses-squares-for-rectangles-but-nothing-for-tria)

[What are/should kids (be) taught about the colour of the
sun?](https://physics.stackexchange.com/questions/394471)




In Japanese, there are two sets of words we learn to describe various kinds of
quadrilaterals.

**Mathematical terms** are 四角形【しかっけい】 _quadrilaterals_ , 台形【だいけい】 _trapezoid_
, 平行四辺形【へいこうしへんけい】 _parallelogram_ , 菱形【ひしがた】 _rhombus_ , 長方形【ちょうほうけい】
_rectangle_ and 正方形【せいほうけい】 _square_. Some are specialized forms of others, as
shown below:

[![enter image description
here](https://i.stack.imgur.com/tC2hA.png)](https://i.stack.imgur.com/tC2hA.png)

If I remember correctly, Japanese people learn these terms in the 4th or 5th
grade. Technically speaking, all 正方形 are also 台形, too. People say yes if
someone asked "Is all 正方形 also 平行四辺形?" in math classes.

However, in reality, people usually use the most specific term when possible,
and unspecific versions are used when they really need them. 菱形のハンカチ normally
refers to a diamond-shaped handkerchief even though a 正方形 is technically a 菱形,
too. In most cases, this is not a _confusion_ but an _optimization_ ;
obviously, it's too bothersome to say 正方形ではない菱形の形をしたハンカチ or 角が90度ではない菱形のハンカチ
in daily life. Likewise, when I hear someone say 長方形 in everyday situation, I
usually assume it's an oblong rectangle.

That said, if I saw "the number of 長方形 is 2" in your example, I would still
argue that it's technically incorrect, too, because they call it a _math
textbook_! So it purely depends on the situation; the more the situation is
closer to math, the stricter you should be.

There is also "easier" or "elementary" set of words suitable for
kindergartners:

  * 四角【しかく】
  * 真四角【ましかく】
  * 長四角【ながしかく】 or 細長い四角

Adults also use them in non-math situations. 四角 (without 形) [usually refers to
squares](https://japanese.stackexchange.com/a/38517/5010) but sometimes
includes rectangles. We should not be too strict on 四角, and we should not use
these words if mathematical strictness is important. 真四角 specifically refers
to squares, and 長四角 specifically refers to oblong rectangles like envelopes.
After all, for kindergartners, people can easily avoid this problem by using
ましかく and ながしかく.




In Japanese, there are two sets of words we learn to describe various kinds of
quadrilaterals.

**Mathematical terms** are 四角形【しかっけい】 _quadrilaterals_ , 台形【だいけい】 _trapezoid_
, 平行四辺形【へいこうしへんけい】 _parallelogram_ , 菱形【ひしがた】 _rhombus_ , 長方形【ちょうほうけい】
_rectangle_ and 正方形【せいほうけい】 _square_. Some are specialized forms of others, as
shown below:

[![enter image description
here](https://i.stack.imgur.com/tC2hA.png)](https://i.stack.imgur.com/tC2hA.png)

If I remember correctly, Japanese people learn these terms in the 4th or 5th
grade. Technically speaking, all 正方形 are also 台形, too. People say yes if
someone asked "Is all 正方形 also 平行四辺形?" in math classes.

However, in reality, people usually use the most specific term when possible,
and unspecific versions are used when they really need them. 菱形のハンカチ normally
refers to a diamond-shaped handkerchief even though a 正方形 is technically a 菱形,
too. In most cases, this is not a _confusion_ but an _optimization_ ;
obviously, it's too bothersome to say 正方形ではない菱形の形をしたハンカチ or 角が90度ではない菱形のハンカチ
in daily life. Likewise, when I hear someone say 長方形 in everyday situation, I
usually assume it's an oblong rectangle.

That said, if I saw "the number of 長方形 is 2" in your example, I would still
argue that it's technically incorrect, too, because they call it a _math
textbook_! So it purely depends on the situation; the more the situation is
closer to math, the stricter you should be.

There is also "easier" or "elementary" set of words suitable for
kindergartners:

  * 四角【しかく】
  * 真四角【ましかく】
  * 長四角【ながしかく】 or 細長い四角

Adults also use them in non-math situations. 四角 (without 形) [usually refers to
squares](https://japanese.stackexchange.com/a/38517/5010) but sometimes
includes rectangles. We should not be too strict on 四角, and we should not use
these words if mathematical strictness is important. 真四角 specifically refers
to squares, and 長四角 specifically refers to oblong rectangles like envelopes.
After all, for kindergartners, people can easily avoid this problem by using
ましかく and ながしかく.

