beeblebrox wrote:
sujoykrdatta : That was an excellent explanation using the most basic concepts! Somehow these concepts never rang a bell in my head while solving!
Any suggestions?
This was a tough one. So it's okay to not have got the method in one go.
What I try doing in these cases is draw the diagram.
I drew a rough circle - assume that radius 200*rt2 and approximated a length equal to 200 and took that as the chord
How to approximately mark 200?
200rt2 ~ 200*1.4 = 280. Take half = 140. Take half of the rest again= 70
Add to get almost 200 (you get 210; that's okay)
- Shown as I in the diagram below.
That gave me the diagram and I realised that the longer side will pass above the center on the same side as the other chords.
// Just for the sake of clarity, I have shown the error you get if you draw the 4th side on the other side of the center.
- Shown as II in the diagram below
(This is not required as a part of the solution) //
Attachment:
IMG_20210426_023459__01.jpg [ 1.25 MiB | Viewed 492 times ]
So, sketching often leads to better idea generation Now, once the correct diagram is done, I tried finding the angle relationships
Whenever there is a circle and the center is involved, I think of
1. Perpendicular from center bisects chord - this can also be used to solve - but is too long
2. Angle at center is twice at center
3. Radii are always equal and hence lead to isosceles triangles
Here #2 worked
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