Tuesday, November 24, 2015
[S1_20151124AESR] Slanted Rectangle does not need Pythagoras
This is another “Bonus Question” at a secondary level from somewhere that the question poser did not mention, but I guess it is most likely an Integrated Programme school in
. It is a beautifully crafted question. The presence of a slant line seems to necessitate
the usage of Pythagoras’ Theorem. However,
we have seen that Pythagoras’ Theorem can actually be avoided even in Primary
(Elementary) School problems. So a 10
year old kid with a rudimentary knowledge of algebra could do this. Can you spot a short cut? Singapore
Stare at the diagram for a while. What do you observe?
area of DDBnCn = ½ of the area of ABnCnD.
area of DDBnCn = ½ of the area of DBnPQ.
\ area of DBnPQ = area of ABnCnD = n cm2.
H04. Look for pattern(s)
H05. Work backwards
H09. Restate the problem in another way
H11. Solve part of the problem
* Lower Secondary Mathematics
* challenge for Primary school Olympiad
* other syllabuses that involve areas and a tiny bit of algebra
* anyone game itching for a challenge