A circle has a radius of 30 cm. Determine the length of the arc subtended by an angle of 60∘ at the center of the circle.
If the lines AB and CD meet at O point and ∠ BOD = 63° then ∠ BOC =
The sum of 7th terms of the series loga+loga2+loga3 + . . . . . . . . . is