In the adjoining figure ABCD rectangle and, a semi-circle with centre O is inscribed inside the rectangle touching side BC and passing through points A and D, A circle is inscribed inside the rectangle touching the semi-circle and the sides of the rectangle as shown. The ratio of the area of the circle to the area of the semi-circle?
If the radius of a circle is diminished by 10%, then its area is diminished by:
Solid cube of 6 * 6 * 6. This cube is cut into to 216 small cubes. (1 * 1 * 1).the big cube is painted in all its faces. Then how many of cubes are painted at least 2 sides.