The Lune of Hippocrates is a single lune bounded by two circles as shown in the diagram below. Its area is equal to the isosceles right triangle created inside one quadrant of the larger circle.[br][br]The Lunes of Alhazen is an extension of the Lune of Hippocrates, which we investigated in the activity above. The sum of the area of the two lunes is equal to the area of the (right) triangle inscribed in the semicircle.[br][br]For more, see https://en.wikipedia.org/wiki/Lune_of_Hippocrates