What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?
Two semicircle sit on the diameter of a semicircle centre O of twice their radius. Lines through O divide the perimeter into two parts. What can you say about the lengths of these two parts?
A point P is selected anywhere inside an equilateral triangle. What can you say about the sum of the perpendicular distances from P to the sides of the triangle? Can you prove your conjecture?
What do you notice about the quadrilateral PQRS as ABCD changes?
Is the area of PQRS always the same fraction of the area of ABCD and, if so, what is this fraction?
Try to prove your conjectures.
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