P(-6, 1) and Q(6, 6) are the two ends of the diameter of a given circle. Calculate the radius.

The angle of a sector of a circle, radius 10.5cm, is 48°, Calculate the perimeter of the sector

Find the length of a side of a rhombus whose diagonals are 6cm and 8cm

Each of the interior angles of a regular polygon is 140°. How many sides has the polygon?

A cylinder pipe, made of metal is 3cm thick.If the internal radius of the pipe is 10cm.Find the volume of metal used in making 3m of the pipe.