•ABCD is a rhombus. If angle B is 60 degrees and AC is 15 cm, find the perimeter of ABCD.




•find the length of the arc, nearest to the cm, subtending a central angle at 40 degrees if the radius of the circle is 10cm.




•how far from the center is a chord of length 16 of the radius is 10 cm?




•AB is a 10 cm chord in a circle of radius 6cm. If O is the center, find the area of triangle OAB.




•a spherical water tank of 5 m diameter is to be painted on the outside. If a quart of paint can cover an area of 8m squared. How many quarts of paint will be purchased??