Given a square ABCD of sides 10 cm, and using the corners as
centres, construct four quadrants with radius 10 cm each inside the
square. The four arcs intersect at P, Q, R and S. Find the area
enclosed by PQRS.
Diagonals for Area
Stage: 4 Challenge Level:
Prove that the area of a quadrilateral is given by half the
product of the lengths of the diagonals multiplied by the sine of
the angle between the diagonals.
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