Find the area of the shaded region in Fig., if PQ = 24 cm, PR = 7 cm and O is the centre of the circle.

Find the area of the shaded region in Fig. 12.20, if radii of the two concentric circles with centre O are 7 cm and 14 cm respectively and angle AOC=40^@ .

Find the area of the shaded region in fig, if ABCD is a square o fside 14 cm and APD and BPC are semicircles.

Find the area of the shaded region in Fig. 12.16. where ABCD is a square of side 14 cm.

Find the area of the shaded region in fig., where a circular arc of radius 6 cm has been drawn with vertex O of an equilateral triangle OAB of side 12 cm as centre.

A lampshade is made by cutting the top of a hollow cone by a plane parallel to its base. The radii of the top and the base of the shade are 4 cm and 12 cm and the height of the shade is 6 cm. Find the area of the curved surface of the lampshade.

Find the surface area of a sphere of radius 7 cm.

Calculate the area of the designed region in fig. common between the two quadrants of circles of radius 8 cm each.

Find the area of the triangle, the lengths of whose sides are 18 cm, 24 cm and 30 cm.

Find the area of a triangle, two sides of which are 8 cm and 11 cm and the perimeter is 32 cm (see Fig. 12.6).