I don't know if I shall be more inspired in joining MOE or stay away from them....
Question: Find the area of rectangle C.
what is the problem? just flick the big triangle over to get a bigger triangleOriginally posted by CoolMyth:I don't know if I shall be more inspired in joining MOE or stay away from them....![]()
obviouslyOriginally posted by DriftingGuy:what is the problem? just flick the big triangle over to get a bigger triangle![]()
Originally posted by DriftingGuy:what is the problem? just flick the big triangle over to get a bigger triangle![]()
I think some information was omitted from the test paper... e.g. the diagram itselfOriginally posted by CoolMyth:![]()
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Actually, I didn't know being a teacher is so easy also....
Anyhow set question also can....![]()
...Originally posted by CoolMyth:It's just inconsistency lah:
Method 1:
Flip B over:
Hence, area of big triangle = 1/2 * 90 = 45
Area of C = 45 - 16 - 4 = 25cm^2
Method 2:
Ratio:
Since area of triangles A and B is in the ratio 1:4 --> their lengths is in the ratio 1:2
Hence, consider shortest side of triangle A = 1/3 * 6 = 2
Therefore, second shortest side of A = (4*2)/2 = 4 (Manipulate triangle area formula)
--> Longer side of rectangle C = 15 - 4 = 11
--> Area of C = 11 x 2 = 22cm^2
25 not equal to 22!
MOE shall consider giving extra marks to students who write both methods and ended it with "MOE xia suay, LOL!"![]()
Is it? He is assuming that the diagonal of A and B forms a straight line.. If the diagonal is assumed straight then they are similar right?Originally posted by shade343:Cannot use method 2. Triangles not similar.
Seriously, you cannot assume if you set the qn...Originally posted by DriftingGuy:Is it? He is assuming that the diagonal of A and B forms a straight line.. If the diagonal is assumed straight then they are similar right?
The diagonal across the rectangle is supposed to join the two triangles together.Originally posted by shade343:Cannot use method 2. Triangles not similar.
All they have to do is include a footnote "diagonal of A and B forms a straight line"Originally posted by sbst275:Seriously, you cannot assume if you set the qn...
And usually, such qn, there is no way to solve because of the diagonal length