Matthew Fan's answer to Judy's Primary 6 Maths Measurement Singapore question.

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Matthew Fan
Matthew Fan's answer
39 answers (A Helpful Person)
1st
The shaded area is the purple minus the green minus the blue. Note that the green is a rectangle, not a square.

I made a mistake just now with an attempt at a solution as i assumed AEF was a straight line but I was wrong. Can you see why AEF is not a straight line?
Judy
Judy
4 years ago
Thank you
Judy
Judy
4 years ago
Thank you.
J
J
4 years ago
The other way is to add up the area of the 2 quadrants, then subtract the area of the rectangle.

Doing so takes away the excess area that would otherwise be overcounted, as well as the overlap of the two quadrants that would otherwise result in double counting