Stage: 5 Challenge Level: 
 |
Four rods are hinged at their ends to form a
quadrilateral with fixed side lengths.
Show that the quadrilateral has a maximum area when it
is cyclic.
[You may find it helpful to see also the problem
'Bendy Quad' .]
|
Cosine rule. Maximise/minimise/optimise. Mathematical reasoning & proof. Pythagoras' theorem. Chain rule. Graphs. Long problems. Circle theorems. Quadrilaterals. Area formulae.
Published June 2000.
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