A semicircle of radius is drawn with centre and diameter . The line is then extended to the point , such that and are of equal length. An arc of the circle with centre and radius is then drawn so that the line is a tangent to the semicircle at , as shown.
What, in terms of , is the area of triangle ?
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\frac{4r^2}{9}
\frac{2r^2}{3}
r^2
\frac{4r^2}{3}
2r^2
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