Two smaller circles touch a large circle internally and pass through the center O of the larger circle. If the diameter of the bigger circle is 28 cm, thenwhat is the area of the bigger circle which is not enclosed by the two smaller circles (in sq.cm)?
Based on the common features like presence of notochord and dorsal hollow neural system, animals like fishes, amphibians, reptiles, birds along with mammals are included in which Phylum?