1. the shape of the top of a table in a restaurant is that of a sector of a circle with centre O an dang;e bod=90. if bo=od=60cm, find the area of the table and the perimeter of the table top.
2. triangle ABC is right angled at A. semicircles are drawn on AB, AC and BC as diameters. find the area of the shaded region .
3.OPQR is a rhombus , three of whose vertices lie on a circle with centre O. if the area of the rhombus is 32root3 cm sq. , find the radius of the circle.
4.O is the centre of the biggre circle an dAC is the diameter. another circle with AB as diameter is drawn. if AC=54cm and BC=10cm, find the area of the shaded region.